Linux kernel NFS server vulnerability can silently remove POSIX ACLs on widely deployed Linux systems, risking access/control disruption across organizations.
CVE-2026-89672
NFS server bug can silently delete POSIX ACLs via crafted SETACL.
Is CVE-2026-89672 being exploited?
Not confirmed. CVE-2026-89672 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 0.52% probability of exploitation in the next 30 days.
How severe is CVE-2026-89672?
CVE-2026-89672 is rated Critical with a CVSS score of 9.1. 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-2026-89672?
Yes. A fix has been recorded for CVE-2026-89672. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-89672 affect?
CVE-2026-89672 affects Linux kernel nfsd (NFS server), NFSACL v2/v3 SETACL path, Systems exposing NFS to untrusted clients. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-89672?
Update to a patched Linux kernel or apply the provided nfsd SETACL fix.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote NFS client can delete directory/file POSIX ACLs (default or both), causing permission loss, unintended access or denial of service.
Immediate action required
- affected>= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 and < e41d173d9dc735cecb15ab7aa63ecab09338f81b
- affected>= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 and < f951b22dbeec46f2e0fba81cb80d1b0c686b61eb
- affected>= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 and < 37eea38e7898538f0ec5f1eb8b18d8646e4be41c
- affected>= a257cdd0e2179630d3201c32ba14d7fcb3c3a055 and < a3a7e20ed66d3f04d37883c398da8a113b430769
- affected2.6.13
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.