CVE-2026-53394: Linux kernel · nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 7.0.0-31.31~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 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 7.0.0-31.31~24.04.1, 7.0.0-31.31, 7.0.0-1012.12 +7
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 19 Jul 2026
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.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 to affected linux-hwe-edge kernel versions. The fix modifies the retry logic in the NFS server code to prevent memory leaks by reusing allocated objects. Users should update to the fixed kernel versions as provided by their vendor. No additional mitigation is indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's NFS server (nfsd) could cause a memory leak due to a race condition involving pre-allocated openowner objects during NFSv4.0 OPEN retries. This occurs when two threads with the same owner string race, potentially leaking kernel memory. The issue has been fixed by modifying the retry logic to reuse allocated objects instead of overwriting pointers. The vulnerability affects specific linux-hwe-edge kernel versions and has a CVSS score of 7.5 with a medium severity rating.
References
- ubuntu.com/security/CVE-2026-53394 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-53394 (opens in a new tab)
- git.kernel.org/linus/57aee7a35bb12753057c5b65d72d1f46c0e95b07 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)