CVE-2026-89702: Linux kernel · nfsd: size fh_verify server sockaddr slot by xpt_locallen
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% 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 11 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 corrects the buffer sizing in the nfsd_fh_verify and nfsd_fh_verify_err tracepoints to prevent buffer overflow. Users should apply the official kernel updates that include this fix. Since this is a kernel-level vulnerability, upgrading to patched kernel versions is the recommended remediation. No alternative mitigations are indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's NFS daemon (nfsd) tracepoints was resolved. The issue involves a buffer overflow caused by a mismatch in buffer sizing between the declared server sockaddr slot and the actual data copied, leading to potential memory corruption when handling NFSv2/v3-over-UDP requests. This flaw allows writes past the end of a reserved buffer slot, which could impact confidentiality, integrity, and availability. The vulnerability affects specific Linux kernel versions and has a high CVSS score of 9.8. A fix has been implemented by correcting the buffer sizing to match the copy length.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89702 (opens in a new tab)
- git.kernel.org/stable/c/719a10e3f5f868c3c4ac3cf3648c5775d12034bd (opens in a new tab)
- git.kernel.org/stable/c/71d068490098b1d23c63b2345e40675d3a1ca763 (opens in a new tab)
- git.kernel.org/stable/c/7ff8d6363cffff45654ea85e319f7c0c54226012 (opens in a new tab)
- git.kernel.org/stable/c/95d064f9828a20ccca5ae90a17be3e2076f25272 (opens in a new tab)
- ubuntu.com/security/CVE-2026-89702 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89702 (opens in a new tab)
- git.kernel.org/linus/71d068490098b1d23c63b2345e40675d3a1ca763 (opens in a new tab)
- git.kernel.org/stable/c/1c6a4d6c20fd42552ffc2c3dfaed2139c9477ee5 (opens in a new tab)