Use-after-free in Linux kernel - CVE-2026-89703
Published: September 12, 2026
Vulnerability identifier: #VU149103
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89703
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to trigger a use-after-free.
The vulnerability exists due to use-after-free in nfsd4_drop_revoked_stid() when handling FREE_STATEID for admin-revoked delegations. A remote user can cause a freed delegation to be added to cl_revoked to trigger a use-after-free.
Affected software
Linux kernel
How to mitigate CVE-2026-89703
Install security update from vendor's repository.