CVE-2026-23456

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case

State: Published
Severity: 8.2 High
Published: Apr 3, 2026
Updated: Oct 19, 2026
Reserved: Jan 13, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case

In decode_int(), the CONS case calls get_bits(bs, 2) to read a length value, then calls get_uint(bs, len) without checking that len bytes remain in the buffer. The existing boundary check only validates the 2 bits for get_bits(), not the subsequent 1-4 bytes that get_uint() reads. This allows a malformed H.323/RAS packet to cause a 1-4 byte slab-out-of-bounds read.

Add a boundary check for len bytes after get_bits() and before get_uint().

Scores

CVSS	Score	Vector	Source
3.1	8.2 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H	Linux

Weaknesses

CWE-125 Out-of-bounds Read

Affected Products

Product	Versions
LinuxLinux	5e35941d990123f155b02d5663e51a24f816b6f3 to before a2cd54b9348e485d338b3c132338a4410c99afafAffected 5e35941d990123f155b02d5663e51a24f816b6f3 to before c95dc674ebf01ecfb40388b6facfc89b81fed3b7Affected 5e35941d990123f155b02d5663e51a24f816b6f3 to before 41b417ff73a24b2c68134992cc44c88db27f482dAffected 5e35941d990123f155b02d5663e51a24f816b6f3 to before 52235bf88159a1ef16434ab49e47e99c8a09ab20Affected 5e35941d990123f155b02d5663e51a24f816b6f3 to before 774a434f8c9c8602a976b2536f65d0172a07f4d2Affected 5e35941d990123f155b02d5663e51a24f816b6f3 to before 6bce72daeccca9aa1746e92d6c3d4784e71f2ebbAffected 5e35941d990123f155b02d5663e51a24f816b6f3 to before fb6c3596823ec5dd09c2123340330d7448f51a59Affected 5e35941d990123f155b02d5663e51a24f816b6f3 to before 1e3a3593162c96e8a8de48b1e14f60c3b57fca8aAffected
LinuxLinux	2.6.17Affected before 2.6.17Not affected 5.10.253 through 5.10.Not affected 5.15.203 through 5.15.Not affected 6.1.167 through 6.1.Not affected 6.6.130 through 6.6.Not affected 6.12.78 through 6.12.Not affected 6.18.20 through 6.18.Not affected 6.19.10 through 6.19.*Not affected 7.0 and laterNot affected

Product

Versions

LinuxLinux

5e35941d990123f155b02d5663e51a24f816b6f3 to before a2cd54b9348e485d338b3c132338a4410c99afafAffected
5e35941d990123f155b02d5663e51a24f816b6f3 to before c95dc674ebf01ecfb40388b6facfc89b81fed3b7Affected
5e35941d990123f155b02d5663e51a24f816b6f3 to before 41b417ff73a24b2c68134992cc44c88db27f482dAffected
5e35941d990123f155b02d5663e51a24f816b6f3 to before 52235bf88159a1ef16434ab49e47e99c8a09ab20Affected
5e35941d990123f155b02d5663e51a24f816b6f3 to before 774a434f8c9c8602a976b2536f65d0172a07f4d2Affected
5e35941d990123f155b02d5663e51a24f816b6f3 to before 6bce72daeccca9aa1746e92d6c3d4784e71f2ebbAffected
5e35941d990123f155b02d5663e51a24f816b6f3 to before fb6c3596823ec5dd09c2123340330d7448f51a59Affected
5e35941d990123f155b02d5663e51a24f816b6f3 to before 1e3a3593162c96e8a8de48b1e14f60c3b57fca8aAffected

LinuxLinux

2.6.17Affected
before 2.6.17Not affected
5.10.253 through 5.10.*Not affected
5.15.203 through 5.15.*Not affected
6.1.167 through 6.1.*Not affected
6.6.130 through 6.6.*Not affected
6.12.78 through 6.12.*Not affected
6.18.20 through 6.18.*Not affected
6.19.10 through 6.19.*Not affected
7.0 and laterNot affected

References

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