CVE-2026-89537
A flaw in the Linux kernel’s SUNRPC implementation allows a remote attacker to send a specially crafted NFS request that causes the kernel to read past the end of a short Kerberos MIC token. The bug can crash the kernel or corrupt memory, leading to a denial of service. It affects systems that use NFS with Kerberos authentication.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Linux kernel users, especially those running NFS with Kerberos authentication. All distributions that ship the vulnerable kernel version are affected.
Real-world impact
An attacker could send a malicious NFS request to a target system, causing the kernel to crash or become unstable, resulting in a denial of service. In some cases, memory corruption could lead to privilege escalation.
Why this severity
The CVSS score of 9.1 reflects the high impact on confidentiality and availability, the lack of required privileges, and the fact that the attack can be performed remotely without user interaction.
What to do about it
- 011. Verify your current Linux kernel version.
- 022. Update your system’s kernel to the latest available version using your distribution’s package manager (e.g., apt, yum, dnf, zypper).
- 033. Reboot the system to load the updated kernel.
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.