iommu/vt-d: Force requesting ACS when tboot is enabled (CVE-2026-89448) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89448

iommu/vt-d: Force requesting ACS when tboot is enabled

Answer in brief

CVE-2026-89448 records a Unknown severity vulnerability in iommu/vt-d: Force requesting ACS when tboot is enabled. 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 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 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	>=5d990b627537e59a3a2f039ff588a4750e9c1a6a <aaeb81241e802c86be69394f72d49fde3f861fbb \|\| >=5d990b627537e59a3a2f039ff588a4750e9c1a6a <45705a6bfdb283f7b3b509010fd617b72f942537 \|\| >=5d990b627537e59a3a2f039ff588a4750e9c1a6a <87bc611c6c98a41c00feb7b06b0c297dd141a2ae \|\| >=5d990b627537e59a3a2f039ff588a4750e9c1a6a <607432b2618b61df81134be0ef2562b8300c1216	aaeb81241e802c86be69394f72d49fde3f861fbb, 45705a6bfdb283f7b3b509010fd617b72f942537, 87bc611c6c98a41c00feb7b06b0c297dd141a2ae, 607432b2618b61df81134be0ef2562b8300c1216
Linux/Linuxgeneric	2.6.33	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to aaeb81241e802c86be69394f72d49fde3f861fbb if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Force requesting ACS when tboot is enabled Currently the conditions of requesting ACS in detect_intel_iommu() don't include tboot, leading to a possible misconfiguration with ACS disabled (e.g. due to user opts) while iommu is later forced on by tboot_force_iommu(). Fix it by checking tboot in detect_intel_iommu().

Quoted source text, attributed separately from HOL analysis.