CVE-2026-58751 Overview
CVE-2026-58751 is a use-after-free vulnerability [CWE-416] in multiple functions of arm-smmu-v3.c, the Linux kernel driver for the ARM System Memory Management Unit v3. A logic error in the driver allows freed memory to be referenced after deallocation. An attacker with local access and System-level execution privileges can exploit this flaw to achieve local privilege escalation. User interaction is not required for exploitation.
The vulnerability was disclosed in the Android Security Bulletin for September 2026 and affects Android devices that rely on the ARM SMMUv3 driver for I/O memory management.
Critical Impact
Successful exploitation grants an attacker elevated privileges on the target device, potentially enabling kernel-level compromise from a process already running with System privileges.
Affected Products
- Android devices using the Linux kernel arm-smmu-v3 driver
- Google Pixel devices covered by the September 2026 Android Security Bulletin
- Linux kernel builds incorporating the vulnerable arm-smmu-v3.c code paths
Discovery Timeline
- 2026-09-15 - CVE-2026-58751 published to the National Vulnerability Database
- 2026-09-16 - Last updated in NVD database
Technical Details for CVE-2026-58751
Vulnerability Analysis
The flaw resides in the ARM SMMUv3 driver source file arm-smmu-v3.c. The SMMU is a hardware component that translates addresses issued by devices performing Direct Memory Access (DMA), providing isolation between devices and system memory. The driver manages allocation and lifecycle of translation contexts and associated data structures.
Multiple functions in the driver contain a logic error that leads to use-after-free conditions. Freed memory objects remain referenced by other execution paths, allowing subsequent operations to dereference dangling pointers. Because the affected code runs in kernel context, an exploited use-after-free can be leveraged to corrupt kernel memory, hijack control flow, or overwrite privileged data structures.
Exploitation requires local access and pre-existing System execution privileges, so the vulnerability serves as a privilege escalation primitive rather than an initial access vector.
Root Cause
The root cause is a lifecycle management error in arm-smmu-v3.c. The driver frees a memory allocation while other code paths continue to hold references to the same object. When those references are later dereferenced, the kernel operates on memory that may have been reallocated for unrelated purposes. This class of defect is tracked as [CWE-416] Use After Free.
Attack Vector
An attacker executing code with System privileges on the affected device can trigger the vulnerable code paths in the SMMUv3 driver. By racing allocation and free operations, or by manipulating driver state to force the vulnerable sequence, the attacker can control the contents of the freed region before it is dereferenced. This enables corruption of kernel objects and escalation from System to kernel-level execution.
No verified public proof-of-concept code is available. Refer to the Android Security Bulletin September 2026 for authoritative technical details.
Detection Methods for CVE-2026-58751
Indicators of Compromise
- Unexpected kernel oops, panics, or KASAN: use-after-free reports referencing arm_smmu_* symbols in kernel logs
- Processes running with System UID performing anomalous ioctl or device file interactions with SMMU-related kernel interfaces
- Kernel crashes correlated with DMA configuration changes or device driver activity on affected platforms
Detection Strategies
- Enable Kernel Address Sanitizer (KASAN) in test builds to surface use-after-free conditions during device validation
- Monitor dmesg and logcat for stack traces referencing arm-smmu-v3 functions
- Baseline expected behavior of System-privileged processes and alert on deviations that indicate exploitation attempts
Monitoring Recommendations
- Ingest kernel log telemetry from managed Android and Linux endpoints into a centralized data lake for correlation
- Track patch level compliance across the fleet against the September 2026 Android Security Bulletin
- Alert on unauthorized modification of kernel modules or loading of untrusted drivers on affected devices
How to Mitigate CVE-2026-58751
Immediate Actions Required
- Apply the September 2026 Android security patch level to all affected devices as soon as the OEM makes it available
- Inventory Linux systems running the arm-smmu-v3 driver and prioritize kernel updates that incorporate the upstream fix
- Restrict which processes can obtain System privileges and audit existing System-level applications for necessity
Patch Information
Google addressed CVE-2026-58751 in the September 2026 Android Security Bulletin. Device vendors should integrate the fixed arm-smmu-v3.c source and ship the corresponding security patch level to end users. Consult the Android Security Bulletin September 2026 for build identifiers and patch references.
Workarounds
- No official workaround has been published. Patching is the recommended remediation path.
- Reduce attack surface by minimizing the number of applications and services granted System privileges on affected devices
- Enforce device management policies that block installation of unsigned or untrusted applications capable of reaching privileged interfaces
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.