CVE-2026-1671: Activity Log Plugin Info Disclosure Flaw

CVE-2026-1671 Overview

The Activity Log for WordPress plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the winter_activity_log_action() function in all versions up to, and including, 1.2.8. This makes it possible for authenticated attackers, with Subscriber-level access and above, to view potentially sensitive information (e.g., the password of a higher level user, such as an administrator) contained in the exposed log files.

This vulnerability is classified as CWE-862 (Missing Authorization), which occurs when software does not perform an authorization check when an actor attempts to access a resource or perform an action.

Critical Impact

Authenticated attackers with low-privilege Subscriber-level access can access sensitive log files containing administrator credentials and other confidential data.

Affected Products

• Activity Log for WordPress plugin versions up to and including 1.2.8
• WordPress sites using the vulnerable plugin versions
• All user accounts with Subscriber-level access or above on affected sites

Discovery Timeline

• February 12, 2026 - CVE-2026-1671 published to NVD
• February 12, 2026 - Last updated in NVD database

Technical Details for CVE-2026-1671

Vulnerability Analysis

This vulnerability represents a broken access control flaw in the Activity Log for WordPress plugin. The core issue lies in the winter_activity_log_action() function, which fails to implement proper capability checks before allowing access to sensitive log data.

WordPress implements a role-based access control system where different user roles (Administrator, Editor, Author, Contributor, Subscriber) have varying levels of permissions. The Subscriber role is typically the most restricted, intended only for users who can manage their profile and read content. However, due to the missing authorization check in this plugin, even users with this minimal access level can invoke the vulnerable function.

The exposed log files may contain highly sensitive information, including plaintext or hashed passwords of higher-privileged users such as administrators. An attacker who successfully exploits this vulnerability could escalate their privileges by obtaining administrator credentials from the log files.

Root Cause

The root cause is a missing capability check (authorization verification) in the winter_activity_log_action() function. In WordPress plugin development, functions that handle sensitive data or administrative actions should verify that the current user has the appropriate capabilities using functions like current_user_can() before processing the request. The absence of this check allows any authenticated user to access data that should be restricted to administrators only.

Attack Vector

The vulnerability is exploitable over the network by any authenticated user with at least Subscriber-level access. The attack requires no user interaction and has low complexity. An attacker would need to:

1. Obtain or create a low-privilege account (Subscriber) on the target WordPress site
2. Authenticate to the WordPress installation
3. Invoke the winter_activity_log_action() function directly
4. Access the returned log file data containing sensitive information

The vulnerability mechanism involves the missing authorization check in the plugin's log access function. When the winter_activity_log_action() function is called, it fails to verify whether the requesting user has administrative privileges before returning log file contents. This allows any authenticated user to retrieve logs that may contain sensitive data including user credentials. For technical implementation details, refer to the WordPress Change Log Entry and the Wordfence Vulnerability Report.

Detection Methods for CVE-2026-1671

Indicators of Compromise

• Unusual access patterns to WordPress activity log endpoints by low-privilege users
• Multiple requests to plugin AJAX handlers from Subscriber-level accounts
• Log file access events from non-administrative user sessions
• Unexpected authentication attempts using credentials found in exposed logs

Detection Strategies

• Monitor WordPress AJAX requests for calls to winter_activity_log_action() from non-admin users
• Implement logging for all plugin function invocations with user role context
• Review WordPress access logs for suspicious patterns targeting the Activity Log plugin
• Deploy web application firewall rules to detect unauthorized log access attempts

Monitoring Recommendations

• Enable verbose logging on WordPress installations to track plugin function calls
• Configure alerts for Subscriber-level users accessing administrative plugin functions
• Regularly audit user activity logs for signs of privilege escalation attempts
• Monitor for new user account creation that could indicate post-exploitation activity

How to Mitigate CVE-2026-1671

Immediate Actions Required

• Update the Activity Log for WordPress plugin to a version newer than 1.2.8 immediately
• Audit all user accounts for unauthorized access or suspicious activity
• Reset passwords for all administrative accounts as a precautionary measure
• Review activity logs for evidence of exploitation prior to patching

Patch Information

A security patch has been released addressing this vulnerability. The fix is available in the WordPress plugin repository. Administrators should update to the latest version of the Activity Log for WordPress plugin through the WordPress admin dashboard or via the WordPress Plugin Repository.

For more information about this vulnerability, consult the Wordfence Vulnerability Report.

Workarounds

• Temporarily deactivate the Activity Log for WordPress plugin until the update can be applied
• Restrict user registration to prevent attackers from creating Subscriber accounts
• Implement additional access controls at the web server level to limit plugin endpoint access
• Review and remove unnecessary user accounts with Subscriber-level access

# WordPress CLI command to update the plugin
wp plugin update winterlock --path=/var/www/html/wordpress

# Verify current plugin version
wp plugin list --name=winterlock --fields=name,version,status --path=/var/www/html/wordpress

# Deactivate plugin temporarily if update is not immediately possible
wp plugin deactivate winterlock --path=/var/www/html/wordpress