CVE-2026-90036: Linux kernel · NFSD: Prevent client use-after-free during blocked-lock reaping
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in cd489b03587378645fe0d20142a33f1ed60bac98 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 19:56 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in cd489b03587378645fe0d20142a33f1ed60bac98, 9026932ac8be4d0ae01db47f23619a98cc57b671, 7081224a59a0ca4edcd62c068588f4d900199a18 +2
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 16 Sep 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 |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in specific Linux kernel commits identified by their hashes. Users should update to a Linux kernel version that includes these fixes to remediate the vulnerability. No additional mitigation actions are indicated beyond applying the official patch.
Description
CVE-2026-90036 is a critical use-after-free vulnerability in the Linux kernel's NFSD component related to client handling during blocked-lock reaping. The flaw arises when a client reference is dropped prematurely, allowing a concurrent operation to free the client while it is still being accessed, leading to a use-after-free condition. This vulnerability has been fixed in specific Linux kernel commits.
References
- git.kernel.org/stable/c/0d53a47c913d0bce3b5ec35c28cbcca4d015f33d (opens in a new tab)
- git.kernel.org/stable/c/7081224a59a0ca4edcd62c068588f4d900199a18 (opens in a new tab)
- git.kernel.org/stable/c/cd489b03587378645fe0d20142a33f1ed60bac98 (opens in a new tab)
- git.kernel.org/stable/c/6fedb2eaff77554ca7a0deffd2e8bc0d6e8b38b0 (opens in a new tab)
- git.kernel.org/stable/c/9026932ac8be4d0ae01db47f23619a98cc57b671 (opens in a new tab)