SB2026062669 - Use-after-free in Linux kernel ipv6

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-53259)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 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/E:U/U:Clear

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

The vulnerability exists due to a use-after-free in ipv6 anycast address handling in net/ipv6/anycast.c when racing anycast address insertion and device teardown. A local attacker can trigger concurrent anycast join and teardown operations to cause a denial of service.

The issue occurs because a freed ifacaddr6 object can remain linked in the global inet6_acaddr_lst[] hash and later be dereferenced by readers under RCU.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/15be7e9fdbff831fb3e89b83cc337a4f85ad3310
• https://git.kernel.org/stable/c/3a967c498baa976b11d4800dda224c507416e97c
• https://git.kernel.org/stable/c/f723ccaff2fb72b71ae8a9fd283f0dee4d9ae7a3