Kernel-level Ceph vulnerability can cause kernel compromise across servers; Linux kernel is widely deployed and impacts enterprise storage.
CVE-2026-89654
Linux kernel Ceph use-after-free enabling potential kernel compromise.
Is CVE-2026-89654 being exploited?
Not confirmed. CVE-2026-89654 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.41% probability of exploitation in the next 30 days.
How severe is CVE-2026-89654?
CVE-2026-89654 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-89654?
Yes. A fix has been recorded for CVE-2026-89654. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-89654 affect?
CVE-2026-89654 affects Linux kernel (Ceph mdsc/mds code), Servers running Ceph storage or Ceph clients, Major Linux distributions with affected kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-89654?
Apply kernel security updates and reboot Ceph hosts immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Use-after-free in Ceph mdsc sessions can corrupt kernel memory, enabling privilege escalation or remote code execution on affected hosts.
Patch when possible
- affected>= 2f2dc053404febedc9c273452d9d518fb31fde72 and < 21d5be092d947f8d83f76f7ebf3989e7e9230a98
- affected>= 2f2dc053404febedc9c273452d9d518fb31fde72 and < ee611a7509554c4ca1f54f6aefe592fb1df7ea70
- affected2.6.34
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.