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

CVE record · `CVE-2026-89448`

- **Identifiers:** `CVE-2026-89448`
- **State:** Confirmed
- **Severity:** CVSS 9.3 Critical
- **Critical:** Yes: CVSS 9+
- **CNA:** Linux
- **Technologies:** [Linux kernel](https://agentprime.io/advisories/technology/linux-kernel.md)
- **Published:** 11 Sept 2026
- **Updated:** 30 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: Linux) at 11 Sept 2026, 19:43 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Critical

Critical, because:

- CVSS score 9.3: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Linux. Product: Linux.
  - affected: `5d990b627537e59a3a2f039ff588a4750e9c1a6a to before 3fd2b60ea9bd18348f5e971678f31041ef211047` (git)
  - affected: `5d990b627537e59a3a2f039ff588a4750e9c1a6a to before 579eb867d3da63f3b5e32f235925e1daa7ec70d0` (git)
  - affected: `5d990b627537e59a3a2f039ff588a4750e9c1a6a to before aaeb81241e802c86be69394f72d49fde3f861fbb` (git)
  - affected: `5d990b627537e59a3a2f039ff588a4750e9c1a6a to before 45705a6bfdb283f7b3b509010fd617b72f942537` (git)
  - affected: `5d990b627537e59a3a2f039ff588a4750e9c1a6a to before 87bc611c6c98a41c00feb7b06b0c297dd141a2ae` (git)
  - affected: `5d990b627537e59a3a2f039ff588a4750e9c1a6a to before 607432b2618b61df81134be0ef2562b8300c1216` (git)
  - Other versions: unaffected
- Vendor: Linux. Product: Linux.
  - affected: `2.6.33`
  - unaffected: `before 2.6.33` (semver)
  - unaffected: `6.1.191 to 6.1.*, inclusive` (semver)
  - unaffected: `6.6.157 to 6.6.*, inclusive` (semver)
  - unaffected: `6.12.109 to 6.12.*, inclusive` (semver)
  - unaffected: `6.18.50 to 6.18.*, inclusive` (semver)
  - unaffected: `7.2.4 to 7.2.*, inclusive` (semver)
  - unaffected: `7.3 to *, inclusive` (original_commit_for_fix)
  - Other versions: affected

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 9.3 Critical, CVSS 3.1: `CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`, from CNA (Linux)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0014, the 3rd percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 11 Sept 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-89448](https://www.cve.org/CVERecord?id=CVE-2026-89448)
- [NVD: CVE-2026-89448](https://nvd.nist.gov/vuln/detail/CVE-2026-89448)

### References from the CNA

- <https://git.kernel.org/stable/c/3fd2b60ea9bd18348f5e971678f31041ef211047>
- <https://git.kernel.org/stable/c/579eb867d3da63f3b5e32f235925e1daa7ec70d0>
- <https://git.kernel.org/stable/c/aaeb81241e802c86be69394f72d49fde3f861fbb>
- <https://git.kernel.org/stable/c/45705a6bfdb283f7b3b509010fd617b72f942537>
- <https://git.kernel.org/stable/c/87bc611c6c98a41c00feb7b06b0c297dd141a2ae>
- <https://git.kernel.org/stable/c/607432b2618b61df81134be0ef2562b8300c1216>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-89448>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-89448/>. Everything for agents: <https://agentprime.io/llms.txt>.