CVE-2026-80891: Linux kernel · KVM: s390: pci: Validate AIBV and AISB before pinning guest pages
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 4 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 has been implemented in the Linux kernel to validate the AIBV and AISB parameters before pinning guest pages. Users should apply the official kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; users should consult the vendor advisory or kernel update notes for the specific fixed version.
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: pci: Validate AIBV and AISB before pinning guest pages The AIBV holds one bit per MSI-X vector for a given function. The size of the bit vector is derived from the NOI and the AIBVO. If the size of the AIBV exceeds a single page boundary, then reject the request as we cannot safely pin the guest AIBV. Similarly reject the request if the AISB address is not 8-byte aligned as the architecture requires doubleword alignment for the summary bit address. Since the AISBO can address up to 64 bits, the size of the AISB can only be 8 bytes for the function. This also ensures the AISB doesn't exceed a single page boundary.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80891 (opens in a new tab)
- git.kernel.org/stable/c/15df7700dd99f8a37f5c6ed2dcf1e33009cdba47 (opens in a new tab)
- git.kernel.org/stable/c/3a1c64220ede4ac9ef9a3e76f008ff60a34f4c48 (opens in a new tab)
- git.kernel.org/stable/c/868d32ac72cba21c5c6d8a66a814b7c25a3a5c01 (opens in a new tab)
- git.kernel.org/stable/c/b878ba7e28144c9a857bc847d31f3c45413450ac (opens in a new tab)
- git.kernel.org/stable/c/f00ef8efd41440129ccd88f4a1ebebf8d61d297f (opens in a new tab)
- git.kernel.org/stable/c/fbfe683f8b1ae7e40b56bdd6daf5bd671bc3a528 (opens in a new tab)
- ubuntu.com/security/CVE-2026-80891 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80891 (opens in a new tab)
- git.kernel.org/linus/868d32ac72cba21c5c6d8a66a814b7c25a3a5c01 (opens in a new tab)