Vulnerability Description
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.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 2.6.17, < 5.10.253 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/2121f5fbe88daff0f1fc5bc47d359426c74b86b0Patch
- https://git.kernel.org/stable/c/495e97af9e7249ee02b72bb1d0848a6efc3700f4Patch
- https://git.kernel.org/stable/c/633e8f87dad32263f6a57dccdb873f042c062111Patch
- https://git.kernel.org/stable/c/65fa92f79677858b14b9e4b7275f26639afe2710Patch
- https://git.kernel.org/stable/c/9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8Patch
- https://git.kernel.org/stable/c/b652b05d51003ac074b912684f9ec7486231717bPatch
- https://git.kernel.org/stable/c/f173d0f4c0f689173f8cdac79991043a4a89bf66Patch
- https://git.kernel.org/stable/c/f5e4f4e4cdb75ec36802059a94195a31f193da60Patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
FAQ
What is CVE-2026-23455?
CVE-2026-23455 is a vulnerability with a CVSS score of 9.1 (CRITICAL). 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 lengt...
How severe is CVE-2026-23455?
CVE-2026-23455 has been rated CRITICAL with a CVSS base score of 9.1/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-23455?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.