CVE-2026-58728: ARM64 Memory Corruption Race Condition

CVE-2026-58728 Overview

CVE-2026-58728 is a race condition vulnerability in the ARM64_TLBI macro of mmu.h within the Android kernel memory management subsystem. The flaw enables memory corruption that a local attacker can leverage for privilege escalation. Exploitation requires no user interaction and no additional execution privileges beyond an unprivileged local context. The issue is tracked under [CWE-362] (Concurrent Execution using Shared Resource with Improper Synchronization) and was published in the Android Security Bulletin September 2026.

Critical Impact
A local, low-privileged process can trigger memory corruption in the ARM64 translation lookaside buffer invalidation path to escalate privileges to kernel-level execution.

Affected Products

Android (Pixel) devices covered by the September 2026 Security Bulletin
ARM64-based Android kernels implementing the affected mmu.h TLB invalidation macro
Downstream Android distributions incorporating the vulnerable memory management code

Discovery Timeline

2026-09-15 - CVE-2026-58728 published to the National Vulnerability Database
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-58728

Vulnerability Analysis

The vulnerability resides in the ARM64_TLBI operation defined in mmu.h, which handles translation lookaside buffer (TLB) invalidation on ARM64 platforms. TLB invalidation coordinates page table changes across CPU cores and must synchronize carefully to prevent stale translations. A race condition in this path allows concurrent execution flows to observe or manipulate memory management state in an inconsistent order.

The result is memory corruption within kernel-managed structures. An attacker who wins the race can trigger unexpected behavior in the page table walker, leading to controlled corruption of kernel memory. This corruption is the primitive used to gain elevated privileges on the local device.

Exploitation complexity is high because the attacker must reliably win a narrow timing window between TLB invalidation and page table state changes. However, the impact on confidentiality, integrity, and availability is significant once the race is won.

Root Cause

The root cause is improper synchronization within the ARM64 TLB invalidation logic. Concurrent kernel operations touching the same MMU state can interleave in ways the code does not correctly serialize, producing a torn or inconsistent memory management view. This aligns with the [CWE-362] classification for race conditions on shared resources.

Attack Vector

The attack vector is local. An unprivileged application running on the device issues concurrent operations that exercise the ARM64 TLB invalidation path across multiple cores. By repeatedly racing these operations, the attacker corrupts kernel memory and pivots to privileged code execution. No user interaction is required.

No public proof-of-concept code has been released. Refer to the Android Security Bulletin September 2026 for vendor technical details.

Detection Methods for CVE-2026-58728

Indicators of Compromise

Unexpected kernel panics or BUG_ON traces referencing MMU, TLB, or page table walk routines on ARM64 Android devices
Unprivileged processes suddenly executing with elevated UID or capabilities without an authorized privilege transition
SELinux denials followed by successful privileged operations from the same process context

Detection Strategies

Monitor Android device logs (logcat, dmesg) for repeated kernel oops events tied to memory management subsystems
Baseline application behavior on managed devices and alert on processes issuing high-frequency syscalls that stress MMU operations
Correlate crash telemetry from mobile device management (MDM) platforms to identify devices exhibiting patterns consistent with race-condition exploitation attempts

Monitoring Recommendations

Ingest mobile endpoint telemetry into a centralized analytics platform to detect anomalous privilege transitions on Android devices
Track Android patch level compliance across the fleet and flag devices missing the September 2026 security patch level
Review application install events for sideloaded or newly deployed apps preceding kernel instability

How to Mitigate CVE-2026-58728

Immediate Actions Required

Apply the September 2026 Android security patch level to all ARM64-based Android devices in the environment
Prioritize patching for Pixel devices and vendor images covered by the Android Security Bulletin September 2026
Restrict installation of untrusted applications through MDM policy until patches are deployed

Patch Information

Google addressed the vulnerability in the September 2026 Android Security Bulletin. Device manufacturers integrate the fix into their monthly security patch level release. Verify the security patch level under device settings and confirm it reflects 2026-09-01 or later.

Workarounds

Enforce application allow-listing through enterprise mobility management to reduce exposure to untrusted local code
Disable sideloading and require Google Play Protect scanning on managed devices
Segment high-risk mobile devices from sensitive corporate resources until the patch is applied

bash

# Verify Android security patch level via ADB
adb shell getprop ro.build.version.security_patch
# Expected output for remediated devices: 2026-09-01 or later