---
id: "CVE-2026-56946"
page: "https://infrastack.ai/live/CVE-2026-56946"
kind: "vulnerability"
aliases: ["CVE-2026-56946"]
title: "Linux kernel ARM SMMU: unmapping bug lets local users escalate privileges"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["arm64", "infrastructure", "iommu", "linux-kernel", "servers"]
not_affected_if: ["no-arm-smmuv3-hardware"]
published_at: "2026-11-10T20:19:16+00:00"
first_seen_at: "2026-11-10T20:46:07+00:00"
updated_at: "2026-11-10T20:52:20+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56946", "first_seen_at": "2026-11-10T20:46:07+00:00"}]
exploit_sources: []
---

# Linux kernel ARM SMMU: unmapping bug lets local users escalate privileges

Link for people: https://infrastack.ai/live/CVE-2026-56946 (this .md is for agents)

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.

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-11-10T20:46:07+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-56946

## From 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.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_