CVE-2025-39688

Medium

In the Linux kernel, the following vulnerability has been resolved: nfsd: allow SC_STATUS_FREEABLE when searching via nfs4_lookup_stateid() The pynfs DELEG8 test fails when run against nfsd. It acquires a delegation and then lets the lease time out. It then tries to use the deleg stateid and expects to see NFS4ERR_DELEG_REVOKED, but it gets bad NFS4ERR_BAD_STATEID instead. When a delegation is revoked, it's initially marked with SC_STATUS_REVOKED, or SC_STATUS_ADMIN_REVOKED and later, it's marked with the SC_STATUS_FREEABLE flag, which denotes that it is waiting for s FREE_STATEID call. nfs4_lookup_stateid() accepts a statusmask that includes the status flags that a found stateid is allowed to have. Currently, that mask never includes SC_STATUS_FREEABLE, which means that revoked delegations are (almost) never found. Add SC_STATUS_FREEABLE to the always-allowed status flags, and remove it from nfsd4_delegreturn() since it's now always implied.

Package Linux Kernel
Published 2025-04-18
Last modified 2025-11-06
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 6.11.6, 6.12 and later are affected. Fixed in 6.12.23, 6.13.11, 6.14.2, 6.15 and their respective stable series.

Affected from
≥ 6.11.6 ≥ 6.12
Fixed in
✓ 6.12.23 6.12.x ✓ 6.13.11 6.13.x ✓ 6.14.2 6.14.x ✓ 6.15

References

The following references provide additional information about CVE-2025-39688 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

4 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2025-39688?

    CVE-2025-39688 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.11.6 onward and has been patched in 6.12.23, 6.13.11, 6.14.2 and others. CVE-2025-39688 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-39688?

    CVE-2025-39688 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2025-39688?

    Yes — CVE-2025-39688 has been patched. Fixed versions include 6.12.23, 6.13.11, 6.14.2 and others. If you are running Linux kernel 6.11.6 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-39688 actively exploited?

    No — CVE-2025-39688 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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