CVE-2026-74439: Linux kernel · iommu/vt-d: Clear Present bit before tearing down scalable-mode context entry
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.3 Critical · fixed in 7.0.0-1013.13~24.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1013.13~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +13
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 15 Aug 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
Upgrade to a fixed release listed under Affected software.
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.
AI-suggested
A patch is available that corrects the vulnerability by clearing the Present bit before zeroing the scalable-mode context entry and performing appropriate cache invalidations. Users should apply the official Linux kernel updates that include this fix. The vendor advisory confirms that this issue has been resolved in updated kernel versions.
Description
A vulnerability in the Linux kernel's IOMMU VT-d implementation was fixed by ensuring the Present bit is cleared before tearing down scalable-mode context entries. Previously, zeroing the context entry while the Present bit remained set could cause hardware to fetch partially zeroed entries, leading to unpredictable behavior or faults. This flaw was addressed by clearing the Present bit first, flushing it to the IOMMU, invalidating the context cache, and only then zeroing the entry. The issue affects specific Linux kernel versions and has a high CVSS score indicating serious impact.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74439 (opens in a new tab)
- git.kernel.org/stable/c/588718101e8449605f1c7e858fecb7cfa701cdab (opens in a new tab)
- git.kernel.org/stable/c/7fd4077dc92b91b1b844333c0a06bb9e286db10a (opens in a new tab)
- git.kernel.org/stable/c/e9e83bcfe37dc719182500dd823c03ab57d934f0 (opens in a new tab)
- git.kernel.org/stable/c/f46452c3df7a8d8a5addc0926e76ef19ea7da0a0 (opens in a new tab)
- ubuntu.com/security/CVE-2026-74439 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74439 (opens in a new tab)
- git.kernel.org/linus/f46452c3df7a8d8a5addc0926e76ef19ea7da0a0 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)