CVE-2026-89651
A critical flaw in the Linux kernel’s Ceph client can cause an out‑of‑bounds read during session setup, potentially crashing the system. The bug allows a malicious Ceph metadata server to trigger the crash without any user interaction. The issue has been fixed in recent kernel releases.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Linux kernel users running the Ceph client, such as system administrators managing Ceph storage clusters.
Real-world impact
An attacker who controls a Ceph metadata server can send a specially crafted message that causes the client system to crash, resulting in a denial of service.
Why this severity
The CVSS score of 9.8 reflects the vulnerability’s high impact (crash), low attack complexity, and the fact that it requires no authentication or user interaction.
What to do about it
- 01Upgrade your Linux kernel to a version that includes the fix for CVE-2026-89651.
- 02Reboot the system to load the updated kernel.
NVD description
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.