CVE-2025-6590 Overview
CVE-2025-6590 is an Exposure of Sensitive Information to an Unauthorized Actor vulnerability affecting Wikimedia Foundation MediaWiki. The vulnerability is associated with the program file includes/htmlform/fields/HTMLUserTextField.php, which improperly handles user-related data and can expose sensitive information to unauthorized parties.
This information disclosure vulnerability (CWE-200) allows attackers to potentially access sensitive user information through the HTMLUserTextField component, which is used for handling user-related form fields within MediaWiki installations.
Critical Impact
Sensitive user information may be exposed to unauthorized actors through improper handling in the HTMLUserTextField component, potentially compromising user privacy across MediaWiki installations.
Affected Products
- MediaWiki versions through 1.39.12
- MediaWiki versions 1.42.76 through 1.43.1
- MediaWiki version 1.44.0
Discovery Timeline
- 2026-02-02 - CVE-2025-6590 published to NVD
- 2026-02-03 - Last updated in NVD database
Technical Details for CVE-2025-6590
Vulnerability Analysis
This vulnerability resides in the HTMLUserTextField.php file within MediaWiki's form handling infrastructure. The HTMLUserTextField class is responsible for rendering and processing user-related input fields in MediaWiki's HTMLForm system. The vulnerability allows sensitive information to be exposed to unauthorized actors through this component.
The attack requires network access but involves high attack complexity and requires user interaction, making exploitation more difficult but still feasible in targeted scenarios. Successful exploitation could result in low direct confidentiality impact but potentially high subsequent system confidentiality impact, as the exposed information could be leveraged for further attacks.
Root Cause
The root cause of CVE-2025-6590 lies in improper information handling within the HTMLUserTextField.php component. The vulnerability stems from insufficient access controls or improper data sanitization when processing user-related form fields, allowing sensitive information to be inadvertently disclosed to unauthorized parties.
The HTMLUserTextField component processes user input and related data without adequately restricting what information is exposed, leading to potential information leakage through the rendered form fields or associated responses.
Attack Vector
The vulnerability is exploitable over the network and requires both specific preconditions and active user interaction for successful exploitation. An attacker would need to craft specific requests or manipulate the HTMLUserTextField component in a way that triggers the information disclosure.
The attack scenario involves targeting MediaWiki installations where users interact with forms containing HTMLUserTextField components. The attacker could potentially intercept or observe sensitive information exposed through improper handling in this component.
Additional technical details regarding the specific exploitation mechanism can be found in the Wikimedia Task T392746.
Detection Methods for CVE-2025-6590
Indicators of Compromise
- Unusual access patterns to MediaWiki form endpoints containing user-related fields
- Unexpected requests targeting includes/htmlform/fields/HTMLUserTextField.php or related form handlers
- Anomalous user data appearing in logs or responses that should not be publicly accessible
Detection Strategies
- Monitor web server logs for suspicious requests to MediaWiki form-related endpoints
- Implement web application firewall (WAF) rules to detect potential information disclosure attempts
- Review MediaWiki access logs for patterns indicating reconnaissance or exploitation attempts targeting user forms
Monitoring Recommendations
- Enable detailed logging for MediaWiki form submissions and user-related operations
- Configure alerting for unusual access patterns to form handling components
- Implement network-level monitoring for data exfiltration attempts from MediaWiki installations
How to Mitigate CVE-2025-6590
Immediate Actions Required
- Audit current MediaWiki installations to determine if affected versions are in use
- Review access controls and permissions for user-related form components
- Consider implementing additional access restrictions on sensitive form endpoints until patches are applied
- Monitor for any signs of exploitation attempts in production environments
Patch Information
Organizations running affected MediaWiki versions should monitor the official Wikimedia security channels for patch releases. The vulnerability is tracked in Wikimedia Task T392746, which provides updates on the remediation status.
Upgrade MediaWiki installations to patched versions as soon as they become available from the Wikimedia Foundation. Review the official MediaWiki security advisories for specific version guidance.
Workarounds
- Restrict access to MediaWiki administrative interfaces and form endpoints to trusted networks
- Implement additional authentication layers for sensitive MediaWiki operations
- Consider temporarily disabling or restricting access to features utilizing HTMLUserTextField if exploitation risk is deemed high
- Apply web application firewall rules to filter potentially malicious requests targeting the vulnerable component
# Example: Restrict access to MediaWiki form endpoints via Apache configuration
<Directory "/var/www/mediawiki/includes/htmlform">
Require ip 10.0.0.0/8
Require ip 192.168.0.0/16
</Directory>
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
