Linux Kernel nf_conntrack_h323 Zero-Length OOB Read in DecodeQ931
CVE-2026-23455 Published on April 3, 2026
netfilter: nf_conntrack_h323: check for zero length in DecodeQ931()
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.
Products Associated with CVE-2026-23455
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Affected Versions
Linux:- Version 5e35941d990123f155b02d5663e51a24f816b6f3 and below 495e97af9e7249ee02b72bb1d0848a6efc3700f4 is affected.
- Version 5e35941d990123f155b02d5663e51a24f816b6f3 and below f5e4f4e4cdb75ec36802059a94195a31f193da60 is affected.
- Version 5e35941d990123f155b02d5663e51a24f816b6f3 and below 633e8f87dad32263f6a57dccdb873f042c062111 is affected.
- Version 5e35941d990123f155b02d5663e51a24f816b6f3 and below 9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8 is affected.
- Version 5e35941d990123f155b02d5663e51a24f816b6f3 and below b652b05d51003ac074b912684f9ec7486231717b is affected.
- Version 5e35941d990123f155b02d5663e51a24f816b6f3 and below f173d0f4c0f689173f8cdac79991043a4a89bf66 is affected.
- Version 2.6.17 is affected.
- Before 2.6.17 is unaffected.
- Version 6.1.167, <= 6.1.* is unaffected.
- Version 6.6.130, <= 6.6.* is unaffected.
- Version 6.12.78, <= 6.12.* is unaffected.
- Version 6.18.20, <= 6.18.* is unaffected.
- Version 6.19.10, <= 6.19.* is unaffected.
- Version 7.0-rc5, <= * is unaffected.