SB20260812145 - Improper input validation in Linux kernel core

Description

This security bulletin contains information about 1 vulnerability.

1) Improper input validation (CVE-ID: CVE-2026-68386)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper state validation in sockmap update handling in net/core/sock_map.c when processing updates for unhashed UDP sockets. A local user can use a BPF program to look up an unbound UDP socket and then bind the socket to trigger a refcount imbalance and cause a denial of service.

The issue is triggered by a transition of a UDP socket from an unbound state to a bound state, which causes the reference decrement to be skipped and results in a memory leak.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/17b7ef6b86112a4e61cee1e9009a4b318e3225c5
• https://git.kernel.org/stable/c/250474c69bc3fc48a5fc21d7c349f279caad947a
• https://git.kernel.org/stable/c/66efd3368ae10d05e08fbe6425b50fdec7186ac7
• https://git.kernel.org/stable/c/7ffe529e7127411806c8692fb1490f552c629dc2
• https://git.kernel.org/stable/c/8692655da369961128658cf8539334b6a960ecb0