CVE-2026-89708
A critical use‑after‑free flaw exists in the Linux kernel’s NFS server (nfsd). The bug allows an attacker to free a session while the kernel’s RPC subsystem still holds a reference to it, potentially leading to memory corruption. The issue has been fixed in the kernel source code.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Linux systems that run the NFS server (nfsd) and expose NFSv4 services. System administrators and users who rely on NFS for file sharing are the typical audience.
Real-world impact
An attacker who can trigger the flaw could cause the NFS server to crash or, in the worst case, execute arbitrary code with kernel privileges, compromising the entire host.
Why this severity
The CVSS score of 9.8 reflects that the vulnerability is network‑exposed, requires no user interaction, and grants an attacker full control over the affected system.
What to do about it
NVD-referenced vendor advisory
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.