Affects the Linux kernel NFS server (widely deployed); can cause kernel crash or remote code execution, requiring org-wide attention.
CVE-2026-89677
Linux nfsd use-after-free in nfsd4_create_file() allowing kernel crash or RCE
Is CVE-2026-89677 being exploited?
Not confirmed. CVE-2026-89677 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-2026-89677?
CVE-2026-89677 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-2026-89677?
Yes. A fix has been recorded for CVE-2026-89677. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-89677 affect?
CVE-2026-89677 affects Linux kernel (nfsd / NFSv4 servers), Major Linux distributions' kernels prior to the stable patch. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-89677?
Apply vendor kernel updates immediately; restrict NFS access to trusted hosts
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote NFS client can trigger a kernel use-after-free, causing DoS or remote kernel code execution / privilege escalation.
Immediate action required
- affected>= 64a989dbd144e0622371396461b11335459692d2 and < 033e783709ce99662cf81f6abcad746a8da9d35f
- affected>= 64a989dbd144e0622371396461b11335459692d2 and < 3e2c79360c6a89975ec5b5a7d4ef937e4db91a27
- affected7.0
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.