Vulnerability in Linux
CVE-2025-39688
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.
EPSS: 0.006 (44.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Linux — versions 6.11.6, 8dd91e8d31febf4d9cca3ae1bb4771d33ae7ee5a, 6.12
- Linux Linux_kernel — versions 6.12
References
Frequently asked questions
- What is CVE-2025-39688?
- CVE-2025-39688 is a high-severity vulnerability in Linux. CVSS score: 7.5/10. Published 2025-04-18.
- How severe is CVE-2025-39688?
- High severity. CVSS v3 base score is 7.5 out of 10.