CVE-2026-90038 — CRITICAL (9.8)

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: NFSD: Prevent client use-after-free during export state revocation nfsd4_revoke_export_states() has the same use-after-free as nfsd4_revoke_states(): it drops nn->client_lock across revoke_one_stid() and the following read of clp->cl_minorversion, but the stateid reference it holds does not pin the client. A teardown racing the dropped lock can free the client while revoke_one_stid() still dereferences it. exportfs -u drives this path through NFSD_CMD_UNLOCK_EXPORT, so an administrator removing an export can race a client expiry. Skip a client that is already expiring and otherwise pin it with cl_rpc_users under client_lock before dropping the lock, matching nfsd4_revoke_states().

CVSS Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

References

FAQ

What is CVE-2026-90038?

CVE-2026-90038 is a vulnerability with a CVSS score of 9.8 (CRITICAL). In the Linux kernel, the following vulnerability has been resolved: NFSD: Prevent client use-after-free during export state revocation nfsd4_revoke_export_states() has the same use-after-free as nfs...

How severe is CVE-2026-90038?

CVE-2026-90038 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-90038?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.