VulnerabilityPublished 6 Aug 2026Updated 11 Sep 2026

CVE-2026-64591: Linux kernel · iommu/vt-d: Avoid WARNING in sva unbind path

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 7.0.0-1012.12~24.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 7.0.0-1012.12~24.04.1, 7.0.0-1011.11~24.04.1, 7.0.0-31.31~24.04.1 +7

Exploitation evidence

Disclosed: evidence found.
CVE published 6 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-xvw3-8q2r-r787

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected <7.0.0-31.31	Fixed in 7.0.0-31.31
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected <7.0.0-1012.12	Fixed in 7.0.0-1012.12
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected 6.17.0-1003.3 – 7.0.0-1012.12 13 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected 7.0.0-1003.3 – 7.0.0-1011.11 7 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected <7.0.0-1011.11	Fixed in 7.0.0-1011.11
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected <7.0.0-1006.7	Fixed in 7.0.0-1006.7

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 and should be applied by updating to the fixed Linux kernel versions as specified in the Ubuntu security advisories USN-8726-1 and USN-8727-1. After updating, a system reboot is required. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be necessary. No additional mitigation actions are indicated by the vendor.

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Avoid WARNING in sva unbind path The Intel IOMMU driver allows SVA on devices even if they do not support PCI/PRI. Commit 39c20c4e83b9 ("iommu/vt-d: Only handle IOPF for SVA when PRI is supported") modified the SVA bind path to allow this configuration by skipping IOPF enablement when PRI is missing. However, it failed to update the unbind path. This creates an imbalance: the unbind path attempts to disable IOPF for a device that never had it enabled, triggering a WARNING in intel_iommu_disable_iopf(): WARNING: drivers/iommu/intel/iommu.c:3475 at intel_iommu_disable_iopf+0x4f/0x90d Call Trace: <TASK> blocking_domain_set_dev_pasid+0x50/0x70 iommu_detach_device_pasid+0x89/0xc0 iommu_sva_unbind_device+0x73/0x150 xe_vm_close_and_put+0x4d2/0x1200 [xe] Fix this by bypassing IOPF operations for SVA domains on non-PRI hardware in both the bind and unbind paths.

Impact

The vulnerability causes a kernel warning due to an imbalance in IOPF handling in the Intel IOMMU driver, which may affect system stability or reliability. There is no indication from the advisory that this leads to privilege escalation, data corruption, or remote compromise. The impact is therefore limited to potential kernel warnings and related operational issues.

Summary

The Intel IOMMU driver in the Linux kernel allowed SVA on devices lacking PCI/PRI support by skipping IOPF enablement during the bind path but failed to update the unbind path accordingly. This caused the unbind path to attempt disabling IOPF for devices where it was never enabled, triggering a kernel WARNING. The fix ensures that IOPF operations are bypassed for SVA domains on non-PRI hardware in both bind and unbind paths, eliminating the warning and correcting the imbalance. This vulnerability affects multiple Linux HWE kernel versions prior to 7.0.0-31.31 and related versions, and a patch is available from Ubuntu security advisories.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Sep 2026, 17:29 UTC

Technical details

References

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