CVE-2026-89673: Linux kernel · nfsd: fix XDR padding calculation in ff_encode_getdeviceinfo
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.3 Medium.
Data as of 28 Oct 2026, 12:19 UTC
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NExploitation 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 for this vulnerability. Users should update affected Linux kernel versions to incorporate the patch that corrects the XDR padding calculation by using xdr_align_size(). No additional mitigations are specified or required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's NFS server (nfsd) causes incorrect XDR padding calculation in the ff_encode_getdeviceinfo function. This results in the declared length of a data field exceeding the actual encoded data by 2-8 bytes, leaking stale memory content to clients and causing misalignment in decoding subsequent data. The issue affects specific Linux kernel versions and has a medium severity rating.
References
- ubuntu.com/security/CVE-2026-89673 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89673 (opens in a new tab)
- git.kernel.org/linus/ (opens in a new tab)
- git.kernel.org/stable/c/41ebca28e17f84293650598f86bd69532ec1a8e0 (opens in a new tab)
- git.kernel.org/stable/c/62e5949f0dd5ec837af144860ff908369df4c7c9 (opens in a new tab)
- git.kernel.org/stable/c/74015b7be806ad9e21d46f7bd2831df280c6c783 (opens in a new tab)
- git.kernel.org/stable/c/8b989aaec85e1293a871d602590c951fe44b8647 (opens in a new tab)