CVE-2025-61639 Overview
CVE-2025-61639 is an Exposure of Sensitive Information to an Unauthorized Actor vulnerability affecting Wikimedia Foundation MediaWiki. This information disclosure flaw is associated with program files includes/logging/ManualLogEntry.php, includes/recentchanges/RecentChangeFactory.php, and includes/recentchanges/RecentChangeStore.php. The vulnerability allows unauthorized actors to potentially access sensitive information through the affected components.
Critical Impact
Sensitive information may be exposed to unauthorized actors through MediaWiki's logging and recent changes functionality, potentially compromising user privacy and system confidentiality.
Affected Products
- MediaWiki versions prior to 1.39.14
- MediaWiki versions prior to 1.43.4
- MediaWiki versions prior to 1.44.1
Discovery Timeline
- 2026-02-03 - CVE CVE-2025-61639 published to NVD
- 2026-02-03 - Last updated in NVD database
Technical Details for CVE-2025-61639
Vulnerability Analysis
This vulnerability falls under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), indicating that the affected MediaWiki components may inadvertently disclose sensitive data to users who should not have access to it. The flaw is network-accessible, meaning remote attackers can potentially exploit it without requiring authentication or user interaction.
The vulnerability specifically affects the logging and recent changes subsystems within MediaWiki. The affected files—ManualLogEntry.php, RecentChangeFactory.php, and RecentChangeStore.php—are responsible for recording and displaying wiki activity. When improperly handled, these components may expose information that should remain restricted, such as user actions, internal system details, or other sensitive metadata.
Root Cause
The root cause stems from improper information handling within MediaWiki's logging and recent changes infrastructure. The affected PHP files (ManualLogEntry.php, RecentChangeFactory.php, and RecentChangeStore.php) fail to adequately restrict access to sensitive information, allowing unauthorized actors to view data that should be protected. This represents a breakdown in the principle of least privilege, where information is made available to entities that do not require access to perform their intended functions.
Attack Vector
The attack vector for this vulnerability is network-based, allowing remote exploitation. An attacker can potentially access sensitive information by interacting with MediaWiki's logging or recent changes functionality through standard HTTP requests. The exploitation does not require special privileges but does depend on certain preconditions being met (as indicated by the attack complexity requiring specific conditions).
The vulnerability manifests in how the logging and recent changes components handle and display information. Attackers may be able to view restricted log entries or recent change details by crafting requests that bypass normal access controls. For technical details, refer to the Wikimedia Task Detail.
Detection Methods for CVE-2025-61639
Indicators of Compromise
- Unusual access patterns to MediaWiki logging endpoints or recent changes pages
- Unexpected queries targeting ManualLogEntry.php, RecentChangeFactory.php, or RecentChangeStore.php
- Anomalous user activity attempting to access restricted log information
- Increased traffic to Special:Log or Special:RecentChanges with unusual parameters
Detection Strategies
- Monitor web server access logs for suspicious requests to MediaWiki's logging and recent changes endpoints
- Implement application-level logging to track access attempts to sensitive log data
- Deploy web application firewalls (WAF) with rules to detect information disclosure attempts
- Review MediaWiki's internal audit logs for unauthorized access patterns
Monitoring Recommendations
- Enable detailed logging for MediaWiki's logging subsystem to track access attempts
- Set up alerts for unusual patterns of access to recent changes and log viewing functionality
- Monitor for bulk data extraction attempts through the affected components
- Regularly review access permissions for sensitive MediaWiki features
How to Mitigate CVE-2025-61639
Immediate Actions Required
- Upgrade MediaWiki to version 1.39.14, 1.43.4, or 1.44.1 depending on your current release branch
- Review MediaWiki access controls and permissions for logging functionality
- Audit existing logs for evidence of unauthorized information access
- Implement network-level access restrictions to limit exposure
Patch Information
Wikimedia Foundation has released patches addressing this vulnerability in MediaWiki versions 1.39.14, 1.43.4, and 1.44.1. Organizations should upgrade to the appropriate patched version based on their current MediaWiki deployment. For detailed patch information and additional context, refer to the Wikimedia Task Detail.
Workarounds
- Restrict network access to MediaWiki installations to trusted IP ranges where possible
- Review and tighten user permissions for accessing log and recent changes features
- Consider temporarily disabling or restricting access to the Special:Log and Special:RecentChanges pages until patching is complete
- Implement additional access controls at the web server or reverse proxy level
# Configuration example - Restrict access to sensitive endpoints via Apache
<LocationMatch "^/wiki/Special:(Log|RecentChanges)">
Require ip 192.168.1.0/24
Require ip 10.0.0.0/8
</LocationMatch>
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
