KVM: s390: pci: Validate AIBV and AISB before pinning guest pages (CVE-2026-80891) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-80891

KVM: s390: pci: Validate AIBV and AISB before pinning guest pages

Answer in brief

CVE-2026-80891 records a Unknown severity vulnerability in KVM: s390: pci: Validate AIBV and AISB before pinning guest pages. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 4, 2026Updated Sep 4, 2026Source checked Sep 4, 2026First seen by HOL Sep 4, 2026Material review Sep 4, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=3c5a1b6f0a18520a0edd0600fef6f1a8553b8fdc <3a1c64220ede4ac9ef9a3e76f008ff60a34f4c48 \|\| >=3c5a1b6f0a18520a0edd0600fef6f1a8553b8fdc <f00ef8efd41440129ccd88f4a1ebebf8d61d297f \|\| >=3c5a1b6f0a18520a0edd0600fef6f1a8553b8fdc <15df7700dd99f8a37f5c6ed2dcf1e33009cdba47 \|\| >=3c5a1b6f0a18520a0edd0600fef6f1a8553b8fdc <b878ba7e28144c9a857bc847d31f3c45413450ac \|\| >=3c5a1b6f0a18520a0edd0600fef6f1a8553b8fdc <fbfe683f8b1ae7e40b56bdd6daf5bd671bc3a528 \|\| >=3c5a1b6f0a18520a0edd0600fef6f1a8553b8fdc <868d32ac72cba21c5c6d8a66a814b7c25a3a5c01	3a1c64220ede4ac9ef9a3e76f008ff60a34f4c48, f00ef8efd41440129ccd88f4a1ebebf8d61d297f, 15df7700dd99f8a37f5c6ed2dcf1e33009cdba47, b878ba7e28144c9a857bc847d31f3c45413450ac, fbfe683f8b1ae7e40b56bdd6daf5bd671bc3a528, 868d32ac72cba21c5c6d8a66a814b7c25a3a5c01
Linux/Linuxgeneric	6.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 3a1c64220ede4ac9ef9a3e76f008ff60a34f4c48 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 4, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 4, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.