A Linux kernel NFS server race causes memory corruption and potential kernel RCE. Linux is ubiquitous on servers; this can disrupt enterprise infrastructure and requires org-wide attention.
CVE-2026-93221
Race in Linux nfsd can cause double-free leading to kernel memory corruption and possible RCE.
Is CVE-2026-93221 being exploited?
Not confirmed. CVE-2026-93221 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.
How severe is CVE-2026-93221?
CVE-2026-93221 is rated High with a CVSS score of 8.1. 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-2026-93221?
Yes. A fix has been recorded for CVE-2026-93221. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-93221 affect?
CVE-2026-93221 affects Linux kernel (nfsd - NFS server), Linux distributions using affected kernels, Servers exporting NFS shares. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-93221?
Install vendor/kernel updates for nfsd and reboot NFS servers immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Concurrent NFS operations can trigger double-free/memory corruption in nfsd, enabling remote code execution or kernel crash (DoS) on NFS servers.
Immediate action required
- affected>= 362063a595be959bc08f4163e6405a0266740091 and < df5922fe09a8131c793ffa86adf204999b0470f8
- affected>= 362063a595be959bc08f4163e6405a0266740091 and < 11a5fe42e1811f793e04ef885b639ea7668f439d
- affected5.2
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.