#VU124910 Out-of-bounds read in Linux kernel - CVE-2026-23455
Published: April 6, 2026
Vulnerability identifier: #VU124910
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-23455
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Linux kernel
Linux kernel
Software vendor:
Linux Foundation
Linux Foundation
Description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in DecodeQ931() in the nf_conntrack_h323 netfilter component when parsing a crafted Q.931 packet with a zero UserUserIE length field. A remote attacker can send a specially crafted packet to disclose sensitive information.
The issue occurs because a 16-bit length value is decremented by 1 to skip the protocol discriminator byte, and an encoded length of 0 wraps to -1 and is then passed to DecodeH323_UserInformation() as a large value.
Remediation
Install security update from vendor's repository.
External links
- https://git.kernel.org/stable/c/495e97af9e7249ee02b72bb1d0848a6efc3700f4
- https://git.kernel.org/stable/c/633e8f87dad32263f6a57dccdb873f042c062111
- https://git.kernel.org/stable/c/9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8
- https://git.kernel.org/stable/c/b652b05d51003ac074b912684f9ec7486231717b
- https://git.kernel.org/stable/c/f173d0f4c0f689173f8cdac79991043a4a89bf66
- https://git.kernel.org/stable/c/f5e4f4e4cdb75ec36802059a94195a31f193da60