CVE-2025-26436 in Android
Summary
by MITRE • 09/04/2025
In clearAllowBgActivityStarts of PendingIntentRecord.java, there is a possible way for an application to launch an activity from the background due to BAL Bypass. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/06/2025
The vulnerability identified as CVE-2025-26436 resides within the PendingIntentRecord.java component of Android's framework, specifically in the clearAllowBgActivityStarts method. This flaw represents a significant security weakness that allows malicious applications to bypass background activity restrictions through a mechanism known as BAL (Background Activity Launch) bypass. The vulnerability operates at the system level where Android's security model typically prevents applications from launching activities from the background to maintain user experience and prevent abuse. However, this particular flaw creates an unintended pathway that undermines these protective measures.
The technical implementation of this vulnerability stems from insufficient validation within the PendingIntentRecord.java file where the clearAllowBgActivityStarts method fails to properly enforce background activity launch restrictions. This method appears to handle the clearing of background activity start permissions, but due to inadequate boundary checks or permission validation, it allows unauthorized applications to circumvent the normal security controls that would typically prevent such background activity launches. The flaw essentially creates a backdoor where applications can request or obtain elevated privileges to start activities in the background without proper authorization, effectively bypassing the Android security model's intended protections.
From an operational perspective, this vulnerability presents a severe risk for local privilege escalation attacks. The flaw requires no additional execution privileges or user interaction to exploit, making it particularly dangerous as it can be leveraged by any application that can manipulate the PendingIntentRecord component. Attackers can exploit this vulnerability to launch malicious activities from the background, potentially gaining access to sensitive data, performing unauthorized operations, or establishing persistent access to the device. The lack of user interaction requirement means that exploitation can occur silently in the background, making detection and prevention significantly more challenging for both users and security systems.
The impact of this vulnerability extends beyond simple privilege escalation, as it can enable broader exploitation vectors within the Android ecosystem. This type of vulnerability aligns with CWE-284 (Improper Access Control) and could potentially map to ATT&CK technique T1068 (Local Privilege Escalation) or T1546 (Event Triggered Execution) depending on how the exploit is implemented. Security researchers categorize this as a critical-level vulnerability due to its ability to bypass fundamental Android security controls without requiring additional attack vectors or user engagement. The vulnerability essentially weakens the Android security boundary between foreground and background applications, potentially allowing malicious actors to perform actions that should be restricted to foreground applications only.
Mitigation strategies for CVE-2025-26436 should focus on immediate patching of affected Android versions and implementation of additional runtime monitoring to detect unauthorized background activity launches. Organizations should implement strict application permission controls and regularly audit background activity launches to identify potential exploitation attempts. The Android security model should be enhanced with additional validation checks in the PendingIntentRecord.java component to ensure that background activity start permissions cannot be bypassed through the clearAllowBgActivityStarts method. System administrators should also consider implementing mobile device management solutions that can monitor and restrict suspicious background activity patterns, as well as maintain updated threat intelligence feeds to identify potential exploitation attempts targeting this specific vulnerability.