CVE-2026-89448: Linux kernel · iommu/vt-d: Force requesting ACS when tboot is enabled
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.3 Critical.
Data as of 28 Oct 2026, 01:00 UTC
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 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.
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().
References
- ubuntu.com/security/CVE-2026-89448 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89448 (opens in a new tab)
- git.kernel.org/linus/607432b2618b61df81134be0ef2562b8300c1216 (opens in a new tab)
- git.kernel.org/stable/c/45705a6bfdb283f7b3b509010fd617b72f942537 (opens in a new tab)
- git.kernel.org/stable/c/607432b2618b61df81134be0ef2562b8300c1216 (opens in a new tab)
- git.kernel.org/stable/c/87bc611c6c98a41c00feb7b06b0c297dd141a2ae (opens in a new tab)
- git.kernel.org/stable/c/aaeb81241e802c86be69394f72d49fde3f861fbb (opens in a new tab)