CVE-2026-23455
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 1.34% probability · 70th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.