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.
Affected products
linux: linux kernel
References10
- git.kernel.org/stable/c/2121f5fbe88daff0f1fc5bc47d359426c74b86b0 Patch
- git.kernel.org/stable/c/495e97af9e7249ee02b72bb1d0848a6efc3700f4 Patch
- git.kernel.org/stable/c/633e8f87dad32263f6a57dccdb873f042c062111 Patch
- git.kernel.org/stable/c/65fa92f79677858b14b9e4b7275f26639afe2710 Patch
- git.kernel.org/stable/c/9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8 Patch
- git.kernel.org/stable/c/b652b05d51003ac074b912684f9ec7486231717b Patch
- git.kernel.org/stable/c/f173d0f4c0f689173f8cdac79991043a4a89bf66 Patch
- git.kernel.org/stable/c/f5e4f4e4cdb75ec36802059a94195a31f193da60 Patch
- cert-portal.siemens.com/productcert/html/ssa-019113.html
- cert-portal.siemens.com/productcert/html/ssa-082556.html
Metrics
- CVSS 3.1
-
9.1
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H - EPSS — exploit probability
- 2% percentile: 76 · as of 12 November 2026
- CWE
- CWE-125
Could this be exploited in your environment?
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