CVE-2026-58820: Memory Safety Privilege Escalation Flaw

CVE-2026-58820 Overview

CVE-2026-58820 is a memory safety vulnerability in Android caused by an integer overflow appearing in multiple code locations. The flaw allows a local attacker to trigger heap-based memory corruption [CWE-122] without requiring additional execution privileges. Successful exploitation results in local escalation of privilege on affected devices.

The vulnerability was disclosed in the Android Security Bulletin September 2026. Attackers with a foothold on the device, such as through a malicious application, can leverage this issue to gain elevated privileges within the Android runtime environment.

Critical Impact
Local privilege escalation with high impact to confidentiality, integrity, and availability, requiring only low-privileged local access and no user interaction.

Affected Products

Android (multiple components affected across several code locations)
See the Android Security Bulletin September 2026 for the specific version matrix
Devices pending the 2026-09-01 security patch level

Discovery Timeline

2026-09-08 - CVE-2026-58820 published to the National Vulnerability Database
2026-09-09 - Last updated in the NVD database

Technical Details for CVE-2026-58820

Vulnerability Analysis

The vulnerability is an integer overflow that occurs in multiple locations within the affected Android components. When arithmetic operations on size or length values wrap around the integer boundary, subsequent memory allocations receive undersized buffers. Later writes into those buffers overflow adjacent heap memory, corrupting metadata or object pointers.

The classification as a heap-based buffer overflow [CWE-122] indicates that the corruption occurs in dynamically allocated memory. An attacker who controls the input driving the overflowed calculation can shape the heap layout to overwrite security-relevant structures. This provides a path from a low-privileged local context to elevated privileges within the Android system.

Because the flaw appears in multiple locations, remediation requires a coordinated patch rather than a single point fix. The Android Security Bulletin consolidates the affected components under the 2026-09-01 patch level.

Root Cause

The root cause is unchecked arithmetic on values that determine allocation sizes or loop bounds. When these values overflow, the runtime allocates less memory than the code subsequently attempts to use. The absence of overflow-safe arithmetic primitives or explicit bounds validation permits the wraparound to reach the allocator.

Attack Vector

Exploitation requires local access with low privileges. A malicious application installed on the device, or code executed within a low-privileged context, can supply crafted inputs to reach the vulnerable code paths. No user interaction is required after the attacker gains initial local execution.

No public proof-of-concept or exploit code has been released. Technical details are limited to what Google published in the Android Security Bulletin September 2026.

Detection Methods for CVE-2026-58820

Indicators of Compromise

Unexpected native crashes or SIGSEGV signals in system processes referenced by the Android bulletin
Applications requesting or obtaining privileges beyond their declared manifest scope
Anomalous logcat entries showing heap corruption traces from affected components

Detection Strategies

Inventory Android devices in the fleet and compare their reported security patch level against 2026-09-01 or later
Monitor mobile device management telemetry for devices running unpatched builds
Review installed applications for unsigned or sideloaded packages that could serve as the initial local foothold

Monitoring Recommendations

Enable centralized collection of crash reports from managed Android devices
Track privilege escalation events reported by mobile threat defense agents
Alert on installations from unknown sources on enrolled corporate devices

How to Mitigate CVE-2026-58820

Immediate Actions Required

Apply the Android security patch level 2026-09-01 or later on all managed devices
Contact device OEMs to confirm the availability of the September 2026 patch for specific hardware models
Restrict installation of applications from untrusted sources through mobile device management policy

Patch Information

Google addressed CVE-2026-58820 in the September 2026 Android security patch level 2026-09-01. Refer to the Android Security Bulletin September 2026 for the definitive list of fixed components and the corresponding AOSP references.

Workarounds

No vendor-supplied workaround is documented; apply the vendor patch
Reduce exposure by removing untrusted applications and disabling sideloading until patched builds are deployed
Enforce the principle of least privilege for installed applications through runtime permission review

bash

# Verify the security patch level on a connected Android device
adb shell getprop ro.build.version.security_patch
# Expected output: 2026-09-01 or later