CVE-2026-23455

Vulnerability overview

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.

Affected product and versions

Product

Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP

Affected versions

>= 5e35941d990123f155b02d5663e51a24f816b6f3 < 2121f5fbe88daff0f1fc5bc47d359426c74b86b0, >= 5e35941d990123f155b02d5663e51a24f816b6f3 < 65fa92f79677858b14b9e4b7275f26639afe2710, >= 5e35941d990123f155b02d5663e51a24f816b6f3 < 495e97af9e7249ee02b72bb1d0848a6efc3700f4, >= 5e35941d990123f155b02d5663e51a24f816b6f3 < f5e4f4e4cdb75ec36802059a94195a31f193da60, >= 5e35941d990123f155b02d5663e51a24f816b6f3 < 633e8f87dad32263f6a57dccdb873f042c062111, >= 5e35941d990123f155b02d5663e51a24f816b6f3 < 9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8, >= 5e35941d990123f155b02d5663e51a24f816b6f3 < b652b05d51003ac074b912684f9ec7486231717b, >= 5e35941d990123f155b02d5663e51a24f816b6f3 < f173d0f4c0f689173f8cdac79991043a4a89bf66, >= 2.6.17, >= V3.1.6, >= V3.1.5, >= 2.6.17 < 5.10.253, >= 5.11 < 5.15.203, >= 5.16 < 6.1.167, >= 6.2 < 6.6.130, >= 6.7 < 6.12.78, >= 6.13 < 6.18.20, >= 6.19 < 6.19.10, 7.0

Fixed versions

5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.20, 6.19.10

Technical data

CVSS vector

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

CWE

CWE-125