Overview

CVE-2025-26436 is a high-risk vulnerability that could potentially allow an application to launch an activity from the background due to BAL Bypass in PendingIntentRecord.java. This could lead to a local escalation of privilege without requiring additional execution privileges. This vulnerability poses a significant risk to any system or data it affects as it could lead to a full system compromise or leakage of sensitive data.

Vulnerability Summary

CVE ID: CVE-2025-26436
Severity: High (7.8 CVSS)
Attack Vector: Local
Privileges Required: None
User Interaction: None
Impact: Local Privilege Escalation, Potential System Compromise, Data Leakage

Affected Products

Product | Affected Versions

Android OS | All versions prior to Vendor Patch

How the Exploit Works

The exploit works by taking advantage of the clearAllowBgActivityStarts function in PendingIntentRecord.java. The function does not properly restrict the launching of background activities, allowing an application to potentially execute activities in the background. This could be used by a malicious application to escalate its privileges locally without requiring additional execution privileges or user interaction.

Conceptual Example Code

A conceptual example of how this exploit might work is not provided due to the potential misuse of such information. However, it involves a malicious application exploiting the clearAllowBgActivityStarts function to initiate background activities and escalate its privileges.

// Pseudocode for malicious activity
public class MaliciousActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Exploit clearAllowBgActivityStarts to start activity in background
Intent intent = new Intent(this, ExploitActivity.class);
startService(intent);
}
}

Please note that the above is a simplified and hypothetical example. The actual exploit would likely involve a more complex sequence of operations.

Mitigation Guidance

To mitigate this vulnerability, users are advised to apply the latest vendor patches once they become available. In the interim, the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation by detecting and blocking attempts to exploit this vulnerability. However, these are not substitute for a proper patch and should be used as a temporary measure only.