CRITICAL: CVE-2026-23455 (CVSS 9.1) — multiple products

CVE: CVE-2026-23455

CVSS: 9.1 (3.1) — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Severity: CRITICAL

Status: Critical advisory

Affected

_See vendor advisory_

Summary

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_h323: check for zero length in DecodeQ931()

In DecodeQ931(), the UserUserIE code path reads a 16-bit length from

the packet, then decrements it by 1 to skip the protocol discriminator

byte before passing it to DecodeH323_UserInformation(). If the encoded

length is 0, the decrement wraps to -1, which is then passed as a

large value to the decoder, leading to an out-of-bounds read.

Add a check to ensure len is positive after the decrement.

Verified Sources

References

https://git.kernel.org/stable/c/2121f5fbe88daff0f1fc5bc47d359426c74b86b0
https://git.kernel.org/stable/c/495e97af9e7249ee02b72bb1d0848a6efc3700f4
https://git.kernel.org/stable/c/633e8f87dad32263f6a57dccdb873f042c062111
https://git.kernel.org/stable/c/65fa92f79677858b14b9e4b7275f26639afe2710
https://git.kernel.org/stable/c/9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8
https://git.kernel.org/stable/c/b652b05d51003ac074b912684f9ec7486231717b
https://git.kernel.org/stable/c/f173d0f4c0f689173f8cdac79991043a4a89bf66
https://git.kernel.org/stable/c/f5e4f4e4cdb75ec36802059a94195a31f193da60

_Validated by the Lyrie Threat Intelligence Pipeline — 3 independent sources confirmed before publication. No speculation._

Lyrie Verdict

A vulnerability of this severity is exactly what Lyrie's anti-rogue-AI defense is built for: continuous, autonomous monitoring that doesn't wait for human reaction time.

#critical