CVE-2026-56946 · Infrastructure
NO FIX YET
A logic error in the Arm SMMUv3 driver (smmu_unmap_visit_leaf in arm-smmu-v3.c) can release DMA page references that are still active during unmapping. A local attacker with system-level execution can use this to escalate privileges.
first public Nov 10, 2026 · 1 source
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Systems with an Arm SMMUv3 IOMMU and its arm-smmu-v3 driver loaded are the ones in scope; the sources do not list affected kernel versions. Machines without Arm SMMUv3 hardware are unlikely to be exposed. unknown for the exact affected ranges.
Not affected if no-arm-smmuv3-hardware
Who cares arm64, iommu, linux-kernel, servers
Unknown from the sources.
No fix yet, per the sources.
In smmu_unmap_visit_leaf of arm-smmu-v3.c, there is a possible way to release active direct memory access page references during unmapping due to a logic error. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.
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