CVE-2026-89674
A critical vulnerability in the Linux kernel's NFS daemon (nfsd) stems from faulty XDR buffer size calculations in the nfsd4_ff_encode_layoutget function. This can result in out-of-bounds writes or the exposure of uninitialized kernel memory to clients. The issue carries a CVSS score of 9.8 and has been addressed in the kernel.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Linux kernels with the vulnerable nfsd code. No specific versions are listed in the provided data, but the issue is in the NFS server implementation.
Real-world impact
An attacker could potentially exploit this to corrupt memory or leak sensitive kernel data, though exploitation would likely require specific conditions (e.g., short strings and odd-sized file handles).
Why this severity
The CVSS vector indicates a network-accessible vulnerability with low complexity, no privileges required, and no user interaction, leading to complete compromise of confidentiality, integrity, and availability.
What to do about it
- 01Consult your Linux distribution's security advisories to identify the specific kernel version that includes this fix.
- 02Upgrade your kernel to that version or a later one.
- 03Reboot the system to load the new kernel.
NVD description of the code fix
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.