CVE-2026-80891

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.

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EPSS — Exploit Prediction

0.0017

Probability of exploitation

0.07%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/15df7700dd99f8a37f5c6ed2dcf1e33009cdba47 https://git.kernel.org/stable/c/3a1c64220ede4ac9ef9a3e76f008ff60a34f4c48 https://git.kernel.org/stable/c/868d32ac72cba21c5c6d8a66a814b7c25a3a5c01 https://git.kernel.org/stable/c/b878ba7e28144c9a857bc847d31f3c45413450ac https://git.kernel.org/stable/c/f00ef8efd41440129ccd88f4a1ebebf8d61d297f https://git.kernel.org/stable/c/fbfe683f8b1ae7e40b56bdd6daf5bd671bc3a528

Frequently Asked Questions

What is CVE-2026-80891? +

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.

How do I check if I'm vulnerable to CVE-2026-80891? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.