CVE-2026-23456

A flaw was found in the Linux kernel's netfilter H.323 connection tracking module. A remote attacker could exploit this vulnerability by sending a specially crafted H.323/RAS (H.323 Registration, Admission, and Status) packet. The system's processing of these packets could lead to an out-of-bounds read of 1-4 bytes, potentially causing information disclosure or a denial of service (DoS).

This vulnerability is remotely exploitable via malformed H.323/RAS network packets. However, exploitation requires the nf_conntrack_h323 module to be loaded, which is only needed for H.323 VoIP traffic traversing NAT. The out-of-bounds read is limited to 1-4 bytes and most likely causes a crash rather than meaningful data leakage.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent the nf_conntrack_h323 module from being loaded. See https://access.redhat.com/solutions/41278 for instructions. This will disable H.323 connection tracking for NAT.