CVE-2026-89675
A critical use‑after‑free bug in the Linux kernel’s NFS server could let an attacker crash or potentially run code by manipulating async copy operations during shutdown or cancellation. The issue was fixed in a kernel patch that corrects race conditions and reference counting in the async copy logic. Users should update to a kernel version that includes this patch.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Linux kernel NFS server (nfsd) in any kernel version before the patch; typical users running NFS server on Linux.
Real-world impact
An attacker could crash the NFS server or potentially execute arbitrary code, leading to denial of service or compromise of the system.
Why this severity
The CVSS score of 9.8 reflects a critical vulnerability that requires no authentication or user interaction and grants full compromise of confidentiality, integrity, and availability.
What to do about it
- 011. Identify the current Linux kernel version you are running.
- 022. Update the kernel to a release that includes the nfsd use‑after‑free fix (any kernel released after the patch that resolved CVE‑2026‑89675).
- 033. Reboot the system to load the updated kernel.
NVD description indicates the vulnerability has been resolved.
Timeline
- Sep 11, 2026 · 2d agoPublishedDisclosed and added to the National Vulnerability Database.
- Sep 13, 2026 · 7h agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.