Use-after-free in Linux kernel - CVE-2026-89663
Published: September 12, 2026
Vulnerability identifier: #VU149145
CSH Severity: Low
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89663
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 NFS server copy-notify stateid revocation logic when revoking copy-notify stateids while concurrent holders retain references. A remote attacker can trigger concurrent copy-notify stateid revocation to cause a denial of service.
The issue involves parent-stateid draining, OFFLOAD_CANCEL handling, and laundromat expiry.
Affected software
Linux kernel
How to mitigate CVE-2026-89663
Install security update from vendor's repository.