CVE-2025-38724: Linux kernel · nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 4.4.0-1159.165 : patch Linux kernel as a priority.
Data as of 11 Nov 2026, 12:28 UTC
- Patch
- Available – fixed in 4.4.0-1159.165, 4.15.0-1207.222~14.04.1, 4.4.0-288.322~14.04.1 +103
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 4 Sep 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 11 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7909-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7910-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7910-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7933-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7938-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8028-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8031-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinux-vmwarepkg:deb/ubuntu/linux-vmware?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?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.
AI-suggested
A patch is available and should be applied promptly. Fixed versions include 4.4.0-1159.165, 4.15.0-1207.222~14.04.1, 4.4.0-288.322~14.04.1, 4.4.0-288.322, 4.4.0-1197.212, and others as listed in the established facts. Users should upgrade to these fixed kernel versions as soon as possible. No alternative mitigations are indicated by the vendor advisory.
Description
A critical use-after-free vulnerability exists in the Linux kernel's NFS server component (nfsd), specifically in the nfsd4_setclientid_confirm() function. The flaw arises because the function did not properly check the return value from get_client_locked(), which could lead to a race condition and subsequent use-after-free. This issue has been fixed by ensuring a reference is obtained early and handling failure cases appropriately.
References
- ubuntu.com/security/CVE-2025-38724 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38724 (opens in a new tab)
- git.kernel.org/linus/908e4ead7f757504d8b345452730636e298cbf68 (opens in a new tab)
- git.kernel.org/stable/c/22f45cedf281e6171817c8a3432c44d788c550e1 (opens in a new tab)
- git.kernel.org/stable/c/36e83eda90e0e4ac52f259f775b40b2841f8a0a3 (opens in a new tab)
- git.kernel.org/stable/c/3f252a73e81aa01660cb426735eab932e6182e8d (opens in a new tab)
- git.kernel.org/stable/c/571a5e46c71490285d2d8c06f6b5a7cbf6c7edd1 (opens in a new tab)
- git.kernel.org/stable/c/74ad36ed60df561a303a19ecef400c7096b20306 (opens in a new tab)
- git.kernel.org/stable/c/908e4ead7f757504d8b345452730636e298cbf68 (opens in a new tab)
- git.kernel.org/stable/c/d35ac850410966010e92f401f4e21868a9ea4d8b (opens in a new tab)
- git.kernel.org/stable/c/d71abd1ae4e0413707cd42b10c24a11d1aa71772 (opens in a new tab)
- git.kernel.org/stable/c/f3aac6cf390d8b80e1d82975faf4ac61175519c0 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7910-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7910-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7933-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7909-5 (opens in a new tab)