CVE-2026-0171: Out-of-Bounds Write RCE Vulnerability

CVE-2026-0171 Overview

CVE-2026-0171 is an out-of-bounds write vulnerability affecting Android, disclosed in the September 2026 Android Security Bulletin. The flaw exists in multiple locations within the code base and stems from a logic error that permits memory writes beyond intended bounds. Exploitation can lead to remote code execution without requiring user interaction and without additional execution privileges. The vulnerability is classified under [CWE-787] (Out-of-bounds Write).

Critical Impact
Attackers with low privileges can achieve remote code execution over the network without user interaction, compromising confidentiality, integrity, and availability of affected Android devices.

Affected Products

Android (per Pixel Security Bulletin, September 2026)
Refer to the Android Security Bulletin September 2026 for the full component and version matrix

Discovery Timeline

2026-09-15 - CVE-2026-0171 published to the National Vulnerability Database (NVD)
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-0171

Vulnerability Analysis

CVE-2026-0171 is an out-of-bounds write flaw resulting from a logic error present in multiple code locations within Android. When triggered, the affected code writes attacker-influenced data past the boundaries of the intended memory region. This corruption can overwrite adjacent structures, function pointers, or control data used later in execution. The result is a path to arbitrary code execution within the context of the vulnerable component.

The vulnerability is reachable over a network interface and does not require any user interaction. According to the Android Security Bulletin, no additional execution privileges are required beyond those already held by the exploited process. This lowers the barrier to weaponization and expands the attack surface across devices exposing the affected code paths.

Root Cause

The root cause is a logic error in bounds-checking or index calculation across several affected code paths. The flawed logic permits a write operation to exceed the allocated buffer, producing memory corruption consistent with [CWE-787]. Because the same class of error appears in multiple locations, remediation requires coordinated patches across the impacted components rather than a single hotfix.

Attack Vector

Exploitation occurs over the network. An attacker sends crafted input that reaches the vulnerable parsing or processing routine, triggering the out-of-bounds write. Successful exploitation corrupts memory structures used to influence control flow, enabling arbitrary code execution. No verified public proof-of-concept code is available at the time of publication. Refer to the Android Security Bulletin September 2026 for component-level technical details.

Detection Methods for CVE-2026-0171

Indicators of Compromise

Unexpected process crashes or SIGSEGV faults in system services referenced by the September 2026 bulletin
Anomalous outbound connections initiated by system-level Android processes
Unexplained privilege changes or process spawning from components not typically executing child processes

Detection Strategies

Monitor Android device telemetry for kernel and userspace crash signatures aligned with components listed in the bulletin
Correlate network-facing service crashes with inbound traffic patterns to identify probing or exploitation attempts
Apply behavioral analytics to flag anomalous code execution patterns originating from vulnerable components

Monitoring Recommendations

Ingest Android security logs and crash reports into a centralized analytics pipeline for retrospective hunting
Track patch level (ro.build.version.security_patch) across the mobile fleet to identify unpatched devices
Alert on outbound connections from Android system processes to untrusted destinations

How to Mitigate CVE-2026-0171

Immediate Actions Required

Apply the September 2026 Android security patch level (2026-09-01 or later) to all affected devices
Inventory devices that have not received the September 2026 patch and prioritize their remediation
Restrict exposure of vulnerable services on untrusted networks until patches are applied

Patch Information

Google addresses CVE-2026-0171 in the September 2026 Android Security Bulletin. Devices receiving the 2026-09-01 security patch level or later contain the fix. Consult the Android Security Bulletin September 2026 for specific build numbers and component-level details relevant to your device fleet.

Workarounds

No vendor-supplied workaround is documented; patching is the required remediation
Reduce risk in the interim by limiting device connectivity to untrusted networks and disabling non-essential network-facing features
Enforce mobile device management (MDM) policies that require the September 2026 patch level for network access

bash

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