Use-after-free in Linux kernel - CVE-2026-89662
Published: September 12, 2026
Vulnerability identifier: #VU149144
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89662
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in the NFSD __destroy_client() function when processing DESTROY_CLIENTID requests. A remote attacker can trigger client teardown while blocked locks are reaped to cause a denial of service.
The race can result in a NULL dereference in remove_blocked_locks().
Affected software
Linux kernel
How to mitigate CVE-2026-89662
Install security update from vendor's repository.