CVE-2025-39688: Linux kernel · nfsd: allow SC_STATUS_FREEABLE when searching via nfs4_lookup_stateid()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 6.11.0-1018.18~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.11.0-1018.18~24.04.1, 6.11.0-1016.16~24.04.1, 6.11.0-28.28~24.04.1 +3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Apr 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7605-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7606-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7605-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7628-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcp-6.11pkg:deb/ubuntu/linux-gcp-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-hwe-6.11pkg:deb/ubuntu/linux-hwe-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-lowlatency-hwe-6.11pkg:deb/ubuntu/linux-lowlatency-hwe-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-nvidia-6.11pkg:deb/ubuntu/linux-nvidia-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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.
References
- ubuntu.com/security/CVE-2025-39688 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-39688 (opens in a new tab)
- git.kernel.org/linus/d1bc15b147d35b4cb7ca99a9a7d79d41ca342c13 (opens in a new tab)
- git.kernel.org/stable/c/52e209203c35a4fbff8af23cd3613efe5df40102 (opens in a new tab)
- git.kernel.org/stable/c/5bcb44e650bc4ec7eac23df90c5e011a77fa2beb (opens in a new tab)
- git.kernel.org/stable/c/d1bc15b147d35b4cb7ca99a9a7d79d41ca342c13 (opens in a new tab)
- git.kernel.org/stable/c/dc6f3295905d7185e71091870119a8c11c3808cc (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7605-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7606-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7605-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7594-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7628-1 (opens in a new tab)