CVE-2026-89541: Linux kernel · SUNRPC: harden gss_unwrap_resp_priv length checks
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 43% 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 hardens the length checks in the gss_unwrap_resp_priv() function to prevent integer overflow and enforce minimum token length. Users should apply the official Linux kernel updates that include this patch. No additional mitigations are indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's SUNRPC subsystem related to the gss_unwrap_resp_priv function has been resolved. The issue involves improper length checks on the RPCSEC_GSS opaque length, allowing crafted replies to cause out-of-bounds reads. This can lead to memory safety issues in the gss_krb5_unwrap_v2 function. The vulnerability has been fixed by implementing stricter bounds checks that prevent integer overflow and enforce minimum token length requirements.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89541 (opens in a new tab)
- git.kernel.org/stable/c/87831b92112c81db251d46756d65daa4f91af6a2 (opens in a new tab)
- git.kernel.org/stable/c/89a15a50f84d32d4b99db86f957427fcbe20a99a (opens in a new tab)
- git.kernel.org/stable/c/d395c30d570ca6168f0297b191709927d1258273 (opens in a new tab)
- git.kernel.org/stable/c/ebcbd2523a8524c3d24e111cdbed8e271d910269 (opens in a new tab)
- ubuntu.com/security/CVE-2026-89541 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89541 (opens in a new tab)
- git.kernel.org/linus/87831b92112c81db251d46756d65daa4f91af6a2 (opens in a new tab)