CVE-2026-90151: Linux kernel · NFSv4: remove callback IDR entry on client allocation failure
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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 17 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
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 fix is available that properly removes the callback identifier during client allocation failure paths before freeing the client. Users should apply the official Linux kernel patches that address this issue. Since this is a kernel-level vulnerability, updating to a patched kernel version is the recommended remediation.
Description
A vulnerability in the Linux kernel's NFSv4 client handling was resolved. The issue involved improper cleanup of callback identifier entries on client allocation failure, potentially leaving stale pointers that could be referenced later. This was discovered via static analysis and manual review. The vulnerability has a high CVSS score of 9.8, indicating critical impact on confidentiality, integrity, and availability.
References
- nvd.nist.gov/vuln/detail/CVE-2026-90151 (opens in a new tab)
- git.kernel.org/stable/c/3f2387e8bfbc4efda5d77c3a11a028d0a119c48f (opens in a new tab)
- git.kernel.org/stable/c/5891c03e150920618db0e9c4ea2d772abacdcfd1 (opens in a new tab)
- git.kernel.org/stable/c/68c721391b761dbe38d5b0094d2bb6e8489ad92b (opens in a new tab)
- git.kernel.org/stable/c/7c4812eb96bdcafb31a65b12f2aa96659429d1d4 (opens in a new tab)
- git.kernel.org/stable/c/80b1c3d5a881f7d9081aa9f46da9742878a0f893 (opens in a new tab)
- git.kernel.org/stable/c/9bfdd0f591307b5198826a0e7a5b2f35f87acd2d (opens in a new tab)
- git.kernel.org/stable/c/d05c2007b3d84ccba11dc6e9cb3202768cc72f14 (opens in a new tab)
- git.kernel.org/stable/c/fc95ca82d5ae598c428ab5a00ae69f8526d59371 (opens in a new tab)
- ubuntu.com/security/CVE-2026-90151 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-90151 (opens in a new tab)
- git.kernel.org/linus/d05c2007b3d84ccba11dc6e9cb3202768cc72f14 (opens in a new tab)