CVE-2025-26421: Google Android Privilege Escalation Vulnerability

CVE-2025-26421 Overview

CVE-2025-26421 is a lock screen bypass vulnerability affecting Google Android versions 13, 14, and 15. The flaw stems from a logic error in multiple code locations within the Android framework and Settings application. An attacker with local access to a locked device can bypass authentication controls and gain limited access to protected content without user interaction. Google addressed the issue in the Android Security Bulletin published on May 1, 2025. The vulnerability is tracked under [CWE-290: Authentication Bypass by Spoofing].

Critical Impact
Local attackers with physical access to a locked Android device can bypass the lock screen due to a logic error, enabling unauthorized access to protected data and local privilege escalation.

Affected Products

Google Android 13.0
Google Android 14.0
Google Android 15.0

Discovery Timeline

2025-09-04 - CVE-2025-26421 published to the National Vulnerability Database
2025-05-01 - Google publishes fix in Android Security Bulletin
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-26421

Vulnerability Analysis

The vulnerability resides in multiple locations across the Android platform, specifically within the frameworks/base component and the Settings application. A logic error in the authentication flow allows an attacker to circumvent the lock screen protection mechanism. Because the flaw is a design-level logic issue rather than a memory corruption defect, exploitation does not require crafted input or elevated execution privileges. The attack requires local access to the device but no user interaction, making it viable in scenarios where a device is momentarily left unattended.

Root Cause

The underlying issue is classified as [CWE-290: Authentication Bypass by Spoofing]. Google's patch commits show changes across both platform/frameworks/base and platform/packages/apps/Settings, indicating that the authentication state check was inconsistently enforced across UI transitions. The logic error permitted an attacker to reach protected surfaces without satisfying the lock screen credential challenge.

Attack Vector

Exploitation is limited to local attackers with physical possession of the target device. An adversary interacts with the locked screen through a specific sequence of UI actions that trigger the flawed logic path. Successful exploitation results in bypassing the credential prompt and reaching content that should be gated behind authentication. The scope of disclosed data is limited to confidentiality impact, and no integrity or availability degradation results from the bypass itself.

See the Android Source Code Commit and the Android Settings App Commit for the exact framework changes.

Detection Methods for CVE-2025-26421

Indicators of Compromise

Devices running Android 13, 14, or 15 with a security patch level earlier than 2025-05-01.
Unexpected access to Settings surfaces or user data on devices that were reportedly locked.
Anomalous session activity or configuration changes originating from a device outside expected user working hours.

Detection Strategies

Query mobile device management (MDM) inventories for the Android security patch level string and flag devices below 2025-05-01.
Correlate physical device custody events (loss, theft, service repair) with subsequent account or configuration changes.
Review enterprise mobility telemetry for unauthorized profile or Settings modifications on managed Android endpoints.

Monitoring Recommendations

Enforce compliance policies via MDM that quarantine devices missing the May 2025 or later Android security patch.
Monitor authentication logs from enterprise applications for sessions initiated from mobile devices without a preceding unlock event.
Track patch adoption rates across the Android fleet and escalate devices that fail to receive the vendor update within a defined SLA.

How to Mitigate CVE-2025-26421

Immediate Actions Required

Apply the Android security patch level 2025-05-01 or later on all affected devices running Android 13, 14, or 15.
Prioritize patching for devices holding sensitive corporate data or credentials.
Require strong lock screen credentials (PIN, password, or biometric) and shorten screen-lock timeout values across the managed fleet.

Patch Information

Google released the fix in the Android Security Bulletin May 2025. The patch modifies both platform/frameworks/base (commit b66817d2) and platform/packages/apps/Settings (commit f16fa584) to enforce consistent authentication state checks. Device manufacturers ship the fix through OEM firmware updates aligned with the May 2025 security patch level.

Workarounds

Enable full-disk or file-based encryption and ensure sensitive apps require a separate authentication step beyond the lock screen.
Disable lock screen features that expose Settings shortcuts or notification content until the device is patched.
Enroll devices in an MDM solution to enforce compliance baselines and remotely wipe lost or stolen hardware.

bash

# Verify the Android security patch level on a device via ADB
adb shell getprop ro.build.version.security_patch
# Expected output for patched devices: 2025-05-01 or later