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CVE-2026-64152 Linux CVE debrief

A vulnerability was found in the Linux kernel's iommu. When iommu_debug is enabled, an unmap error occurs. The issue arises from the map error flow calling iommu_unmap(), which in turn calls iommu_debug_unmap_begin()/iommu_debug_unmap_end(). However, since this is an error path and the map flow never established the original iommu_debug_map(), it malfunctions. To address this, the unmap error handling was lifted into iommu_map_nosync() and reordered to record the partial mapping with trace_map()/iommu_debug_map() and then immediately unmap it. This prevents unbalanced tracking and provides saner tracing. Linux kernel users and administrators should review the official CVE record and NVD detail page for CVE-2026-64152 to understand the potential impact on their systems.

Vendor
Linux
Product
Unknown
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-19
Original CVE updated
2026-07-19
Advisory published
2026-07-19
Advisory updated
2026-07-19

Who should care

Linux kernel users and administrators should be aware of this vulnerability and take necessary actions to ensure their systems are updated. This includes reviewing the official advisory, applying patches for the iommu subsystem, and monitoring system logs for potential issues. Security teams and vulnerability management teams should also review the CVE record and NVD detail page to understand the potential impact on their systems and prioritize remediation efforts.

Technical summary

The Linux kernel's iommu subsystem has a vulnerability related to error handling when iommu_debug is enabled. Specifically, the iommu_map() function does not properly handle unmap errors, leading to potential issues with iommu_debug_unmap_begin() and iommu_debug_unmap_end(). To fix this, the error handling was refactored to occur within iommu_map_nosync(), ensuring that partial mappings are properly recorded and unmapped. This change prevents unbalanced tracking and provides saner tracing. The official CVE record and NVD detail page for CVE-2026-64152 provide more information on the vulnerability and its potential impact.

Defensive priority

Medium

Recommended defensive actions

  • Update Linux kernel to the latest version
  • Review and apply patches for iommu subsystem
  • Monitor system logs for potential issues
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-07-19T16:17:57.170Z and has not been modified since then. The NVD entry is currently Received. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the official advisory. Linux kernel users and administrators should review the official CVE record and NVD detail page for CVE-2026-64152 to understand the potential impact on their systems.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-19T16:17:57.170Z and has not been modified since then.