Linux kernel nfsd affects widely deployed servers; can crash or enable kernel-level compromise, impacting enterprise infrastructure and services.
CVE-2026-89676
NFSv4 async COPY bug causes kernel memory corruption via stale stateid
Is CVE-2026-89676 being exploited?
Not confirmed. CVE-2026-89676 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 0.45% probability of exploitation in the next 30 days.
How severe is CVE-2026-89676?
CVE-2026-89676 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-2026-89676?
Yes. A fix has been recorded for CVE-2026-89676. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-89676 affect?
CVE-2026-89676 affects Linux kernel (nfsd / NFSv4 server). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-89676?
Install vendor/stable kernel updates and restart NFS servers immediately
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote NFS client can trigger kernel use-after-free leading to DoS or potential kernel-level code execution (root) via crafted NFS requests.
Immediate action required
- affected>= e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 and < 9b4e5e9ba5ae13808b8a6d229d87c54611ba0e7a
- affected>= e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 and < 14b978e8d05ce018d0afbeb6611833ef91713a02
- affected>= e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 and < d0beaee498e11880e72826026db0e9c9890fc114
- affected4.20
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.