Use-after-free in Linux kernel - CVE-2026-89564
Published: September 12, 2026
Vulnerability identifier: #VU149238
CSH Severity: Low
CVSS v4: 0 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89564
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to trigger a use-after-free.
The vulnerability exists due to improper socket reference management in IPv4 and IPv6 multicast forwarding paths when processing non-locally deliverable multicast packets. A remote attacker can send a non-locally deliverable multicast packet to trigger a use-after-free.
Exploitation requires the associated prefetched socket to be destroyed before the socket buffer is freed.
Affected software
Linux kernel
How to mitigate CVE-2026-89564
Install security update from vendor's repository.