In Bouncy Castle for Java before 1.85, MTI/A0 DH agreement exponentiates unvalidated peer value. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

In Bouncy Castle for Java before 1.85, JSSE hostname verifier CN-fallback enabled by default despite documented opt-in. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bctls-fips 1.0.24 (1.0.X series), 2.0.24 (2.0.X series) and 2.1.24 (2.1.X series).

In Bouncy Castle for Java before 1.85, Name Constraints bypass via trailing dot in rfc822Name and URI. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).

In Bouncy Castle for Java before 1.85, Stapled OCSP response accepted without binding to the checked certificate. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).

In Bouncy Castle for Java before 1.85, OER parser recurses without depth limit on self-referential IEEE 1609.2 schema. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcutil-fips 2.0.7 (2.0.X series) and 2.1.7 (2.1.X series).

In Bouncy Castle for Java before 1.85, CMS AuthenticatedData content not bound to MAC when authAttrs present. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).

In Bouncy Castle for Java before 1.85, DTLS handshake reassembler allocates buffer from unchecked 24-bit length. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bctls-fips 1.0.24 (1.0.X series), 2.0.24 (2.0.X series) and 2.1.24 (2.1.X series).

In Bouncy Castle for Java before 1.85, CMS verifySignatures returns true for SignedData with zero signers. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).

In Bouncy Castle for Java before 1.85, CCM-family modes write plaintext to caller buffer before tag check. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).

In Bouncy Castle for Java before 1.85, Quadratic-time escaping when stringifying X.500 distinguished names. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).

In Bouncy Castle for Java before 1.85, HSS public-key level count unbounded, enabling huge allocation on verify. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).

In Bouncy Castle for Java before 1.85, Possible OOM from unbounded up-front allocation on a definite-length read. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series), and before bctls-fips 1.0.24.

In Bouncy Castle for Java before 1.85, CMS AuthEnvelopedData fails to enforce tag-length on decryption. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 1.0.12 (1.0.X series), 2.0.12 (2.0.X series) and 2.1.12 (2.1.X series).

In Bouncy Castle for Java before 1.85, RSA PKCS#1 verification skips last two hash bytes in NULL-omitted path. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

In Bouncy Castle for Java before 1.85, IESEngine stream-mode MAC forgery via length-dependent KDF split. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

In Bouncy Castle for Java before 1.85, Lazy ASN.1 sequence forcing resets nesting-depth guard. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 1.0.2.7 (1.0.X series), 2.0.2 (2.0.X series) and 2.1.3 (2.1.X series).

In Bouncy Castle for Java before 1.85, KCCMBlockCipher MAC does not bind nonce when AAD is absent (cross-nonce AEAD forgery). This issue also affects Bouncy Castle for Java LTS before 2.73.12.

The fix released in jackson-core 2.18.6 and 2.21.1 for CVE-2026-18401 (GHSA-72hv-8253-57qq, number length constraint bypass in the non-blocking parser) is incomplete. This record covers the remaining bypass.

The earlier fix wired validateIntegerLength() into a new setIntLength() helper and invoked it wherever the integer portion of a number is decided: a terminator byte arrives, a '.' or 'e'/'E' is seen, or input ends inside a fully buffered value. It was not invoked on the attacker-relevant path where the parser runs out of input while still inside the MINORNUMBERINTEGERDIGITS minor state and returns NOTAVAILABLE to the caller.

As a result, an attacker who streams JSON to a non-blocking parser in many small chunks, without ever sending a terminator byte, keeps the parser inside MINORNUMBERINTEGERDIGITS indefinitely. textBuffer.expandCurrentSegment() grows the accumulator on every chunk while validateIntegerLength() is never called. The accumulator is bounded only by maxStringLength (20 MiB by default) rather than by maxNumberLength (1000 by default), an amplification of roughly 20,000x over the documented limit. Because Java char values occupy two bytes, a single connection can be driven to approximately 40 MiB of heap before the validator finally fires when the value completes.

The equivalent fraction-path code is correct: finishFloatFraction() calls setFractLength() before its NOTAVAILABLE return. The missing call affects the integer-digit paths in startPositiveNumber(), startNegativeNumber() and finishNumberIntegralPart() in NonBlockingUtf8JsonParserBase.

Impact: reactive frameworks such as Spring WebFlux/Reactor, Quarkus, Helidon and Vert.x feed inbound HTTP or gRPC bytes to the async parser as they arrive, which is precisely the chunked-feed shape required. Operators who set StreamReadConstraints.maxNumberLength expecting it to cap memory per number value do not get that guarantee; memory accumulates per concurrent connection and attacker-controlled concurrency can exhaust the JVM heap. The synchronous parsers (UTF8StreamJsonParser, ReaderBasedJsonParser) and the async parser operating on complete input are not affected.

Exploitation requires only the ability to stream data to a parsing endpoint; no privileges or user interaction are needed.

This issue affects com.fasterxml.jackson.core:jackson-core from version 2.15.0 through 2.18.7, and from 2.19.0 through 2.21.3, and tools.jackson.core:jackson-core from 3.0.0 through 3.1.3. Versions prior to 2.15.0 are not affected, because StreamReadConstraints -- which defines the maxNumberLength setting -- was first introduced in jackson-core 2.15.0, so no such constraint exists to be bypassed in earlier releases. Note that GHSA-r7wm-3cxj-wff9 states the affected 2.x range without a lower bound. The 2.22.x and 3.2.x release lines are not affected: those branches were created after the fix commit landed on 2026-05-21 and therefore contain it from their initial releases (2.22.0, tagged 2026-06-03, and 3.2.0, tagged 2026-06-08).

axios in a Node.js deployment using the HTTP adapter can route requests through an attacker-controlled proxy. axios hardens merged request configuration by creating a null-prototype object, but request interceptors run after the merge; a common immutable interceptor pattern such as {...config} or Object.assign({}, config) converts the hardened config back into a regular object. axios then dispatches that object without re-hardening it, and the Node HTTP adapter reads config.proxy through the prototype chain. If an attacker can pollute Object.prototype.proxy, affected requests can be routed through an attacker-controlled proxy. For plaintext HTTP requests, the proxy can observe Authorization headers, Basic auth from config.auth, method, absolute URL, Host, and request body, and can return its own response. This does not establish browser impact or HTTPS header/body disclosure under normal TLS validation. Affected versions are =0.31.1 (fixed in 0.33.0) and =1.15.2 (fixed in 1.18.0).

Summary BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() allowlists any array type based only on clazz.isArray(), without validating the array's component (element) type against the configured allowlist. A PTV built with allowIfSubTypeIsArray() plus an explicit concrete-type allowlist therefore still permits EvilType[] even though EvilType is not allowlisted. When Jackson deserializes the elements and no per-element type IDs are present, it instantiates the component type directly with no further PTV check, bypassing the allowlist.

Impact Applications using BasicPolymorphicTypeValidator with allowIfSubTypeIsArray() as a safeguard get no protection for concrete array component types; an attacker controlling JSON can instantiate non-allowlisted types via an array wrapper, re-opening the gadget-instantiation risk PTV is meant to prevent.

Affected / Patched (verified via git tag --contains) - 2.18 line: >= 2.10.0, < 2.18.8 -> fixed in 2.18.8 - 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4 - 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4

PolymorphicTypeValidator was added in 2.10.0 so vulnerability N/A for versions prior to that.

Severity / CWE Maintainer: significant. Reporter: HIGH. CWE-184 (Incomplete List of Disallowed Inputs); related CWE-502.

Upstream fix FasterXML/jackson-databind#5981; fix PR #5983 (24529da), 2.18 backport PR #5984 (01d1692). Released 2026-06-04 in 2.18.8 / 2.21.4 / 3.1.4.

Credits Omkhar Arasaratnam (@omkhar) - finder.

jackson-databind's PolymorphicTypeValidator (PTV) is the primary safety mechanism guarding polymorphic deserialization. When polymorphic typing is enabled and a type identifier contains generic parameters (i.e. the type ID string contains <), DatabindContext.resolveAndValidateGeneric() validates only the raw container class name (the substring before <) against the configured PTV.

If the container type is approved, the method parses the full canonical type string via TypeFactory.constructFromCanonical() and returns the fully parameterized type without ever validating the nested type arguments against the PTV. The nested type arguments are then resolved, instantiated, and populated as beans during deserialization.

An attacker who controls the type ID can therefore place a denied class as a generic type parameter of an allowed container — for example java.util.ArrayList<com.evil.Gadget> when only java.util.ArrayList is allow-listed. The container passes the PTV check; com.evil.Gadget is loaded via Class.forName(name, true, loader), instantiated, and its properties are set from attacker-controlled JSON. This completely bypasses an explicitly configured PTV allow-list.

This is the same vulnerability class responsible for the historical sequence of jackson-databind deserialization CVEs; here it manifests as a validator bypass rather than a missing deny-list entry.

Impact

- Bypass of the PTV allow-list, including the recommended BasicPolymorphicTypeValidator configured with name-prefix allow rules. - Arbitrary class instantiation of any type assignable to the container's element/parameter position, with attacker-controlled property values (setter/field injection). - Potential unauthenticated remote code execution when a class with exploitable side effects (JNDI lookup, JDBC/connection-pool gadgets,TemplatesImpl-style loaders, etc.) is present on the classpath.

Applications that accept untrusted JSON and rely on a configured PTV — the documented, security-conscious configuration — are affected.

Proof of Concept

Configuration restricting polymorphic deserialization to a single safe container:

java BasicPolymorphicTypeValidator ptv = BasicPolymorphicTypeValidator.builder() .allowIfSubType("java.util.ArrayList") .build();

ObjectMapper mapper = JsonMapper.builder() .polymorphicTypeValidator(ptv) .build();

Malicious payload (Wrapper.value is Object with @JsonTypeInfo(use = Id.CLASS, include = As.WRAPPERARRAY)):

json {"value":["java.util.ArrayList<com.evil.EvilGadget>",[{"cmd":"calc.exe"}]]}

On vulnerable versions, com.evil.EvilGadget is instantiated and its cmd property is set, despite only java.util.ArrayList being allow-listed. On 2.18.8 / 2.21.4 / 3.1.4 the deserialization throws InvalidTypeIdException before instantiation.

Variant payloads (all bypass an ArrayList/HashMap allow-list):

| Type ID | Smuggled type position | |---|---| | java.util.ArrayList<Evil> | list element | | java.util.HashMap<Evil,String> | map key | | java.util.HashMap<String,Evil> | map value | | java.util.ArrayList<java.util.ArrayList<Evil>> | nested element | | java.util.ArrayList<Evil[]> | array element |

---

Patches

Fixed in 2.18.8, 2.21.4 and 3.1.4 via the changes for FasterXML/jackson-databind#5988, commit 434d6c511. The fix adds recursive validation of each non-trivial type parameter (and array element types appearing as parameters) through the full PTV chain, with documented exemptions for Object (wildcard resolution) and Enum types.

PolymorphicTypeValidator was added in 2.10.0 so vulnerability N/A for versions prior to that.

In Bouncy Castle for Java before 1.85, BKS/UBER keystore allocates from untrusted lengths before integrity check. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

In Bouncy Castle for Java before 1.85, BKS keystore accepts legacy version with 16-bit integrity MAC key. This issue also affects Bouncy Castle for Java LTS before 2.73.12.

Apache Log4j Core's Rfc5424Layout

Apache Log4j Core's XmlLayout

The Log4j1XmlLayout from the Apache Log4j 1-to-Log4j 2 bridge fails to escape characters forbidden by the XML 1.0 standard, producing malformed XML output. Conforming XML parsers are required to reject documents containing such characters with a fatal error, which may cause downstream log processing systems to drop or fail to index affected records.

Two groups of users are affected:

Those using Log4j1XmlLayout directly in a Log4j Core 2 configuration file. Those using the Log4j 1 configuration compatibility layer with org.apache.log4j.xml.XMLLayout specified as the layout class.

Users are advised to upgrade to Apache Log4j 1-to-Log4j 2 bridge version 2.25.4, which corrects this issue.

Note: The Apache Log4j 1-to-Log4j 2 bridge is deprecated and will not be present in Log4j 3. Users are encouraged to consult the Log4j 1 to Log4j 2 migration guide

axios versions 0.31.1 before 0.33.0 and 1.15.1 before 1.18.0 contain an incomplete depth-limit bypass in toFormData.js when serializing objects with top-level keys ending in '{}'. Attackers who control object keys and nested values passed to axios form or parameter serialization can trigger a RangeError from JSON.stringify, causing denial of service in the affected request path.

axios versions 0.31.0 before 0.33.0 and 1.15.0 before 1.18.0 fail to recognize 0.0.0.0 as a loopback address in shouldBypassProxy.js, allowing requests to 0.0.0.0 to bypass NOPROXY rules. Attackers can supply 0.0.0.0 URLs to route requests through configured proxies, potentially exposing local services when the proxy can reach the destination.

In Bouncy Castle for Java before 1.85, OpenPGP Argon2 S2K honours attacker-chosen memory and passes. This issue also affects Bouncy Castle for Java LTS before 2.73.12, and Bouncy Castle for Java FIPS (BC-FJA) before bcpg-fips 1.0.13 (1.0.X series), 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).

In Bouncy Castle for Java before 1.85, LDAP filter injection in legacy jdk1.4 LDAPStoreHelper.