CVE-2026-0548: Tutor LMS WordPress Auth Bypass Flaw

CVE-2026-0548 Overview

The Tutor LMS – eLearning and online course solution plugin for WordPress contains a missing authorization vulnerability that allows authenticated attackers to delete arbitrary attachments. The vulnerability exists in the delete_existing_user_photo function across all versions up to and including 3.9.4. Due to a missing capability check, attackers with subscriber-level access or above can exploit this flaw to delete any attachment on the affected WordPress site, potentially disrupting site functionality and removing critical media files.

Critical Impact

Authenticated attackers with minimal privileges (subscriber level) can delete arbitrary attachments across the WordPress site, leading to data loss and potential service disruption.

Affected Products

• Tutor LMS WordPress Plugin versions up to and including 3.9.4
• WordPress sites using vulnerable Tutor LMS installations
• eLearning platforms built on affected Tutor LMS versions

Discovery Timeline

• 2026-01-20 - CVE-2026-0548 published to NVD
• 2026-01-20 - Last updated in NVD database

Technical Details for CVE-2026-0548

Vulnerability Analysis

This vulnerability is classified under CWE-862 (Missing Authorization), a common weakness where the application fails to perform proper authorization checks before executing sensitive operations. In this case, the delete_existing_user_photo function in the Tutor LMS plugin's User.php class does not verify whether the requesting user has sufficient privileges to delete attachments.

WordPress uses a role-based access control system where subscribers represent the lowest authenticated user level with minimal permissions. By default, subscribers should not have the capability to delete media attachments. However, the vulnerable function processes deletion requests without validating the user's capabilities, allowing any authenticated user to delete arbitrary attachments by manipulating the request parameters.

The attack is network-accessible, requires low privileges (any authenticated user), and can be executed without user interaction. The impact includes potential integrity violations through unauthorized file deletion and availability concerns if critical site attachments are removed.

Root Cause

The root cause is a missing capability check in the delete_existing_user_photo function within the classes/User.php file. The function processes attachment deletion requests without calling WordPress's current_user_can() function or equivalent authorization mechanism to verify the requesting user has appropriate permissions to perform the deletion operation.

Attack Vector

The vulnerability can be exploited through the network by any authenticated WordPress user. An attacker would need to:

1. Register or compromise a subscriber-level account on the target WordPress site
2. Identify the AJAX action or endpoint associated with the delete_existing_user_photo function
3. Craft a request specifying the attachment ID to delete
4. Submit the request, bypassing the missing authorization check

The attack does not require any special conditions or complex exploitation techniques. The attacker simply needs valid authentication credentials for any user role and knowledge of attachment IDs, which can often be enumerated through the WordPress media library or by analyzing page source code.

Detection Methods for CVE-2026-0548

Indicators of Compromise

• Unexpected deletion of media attachments, particularly user profile photos and course materials
• Audit log entries showing attachment deletions by subscriber or low-privilege users
• Missing images or media files on course pages and user profiles
• Database records indicating attachment metadata removed without corresponding admin activity

Detection Strategies

• Monitor WordPress activity logs for attachment deletion events initiated by non-administrative users
• Implement file integrity monitoring on the wp-content/uploads directory to detect unexpected deletions
• Review web server access logs for suspicious requests to Tutor LMS AJAX endpoints with deletion parameters
• Enable WordPress debug logging to capture authorization-related function calls

Monitoring Recommendations

• Deploy web application firewall (WAF) rules to detect and block unauthorized attachment deletion attempts
• Configure alerts for bulk or rapid attachment deletion events from low-privilege accounts
• Implement regular backup verification for the WordPress media library
• Set up monitoring for changes to the wp_posts table entries of type "attachment"

How to Mitigate CVE-2026-0548

Immediate Actions Required

• Update Tutor LMS plugin to version 3.9.5 or later immediately
• Audit attachment deletion activity logs for evidence of exploitation
• Review user accounts with subscriber-level access for suspicious activity
• Restore any attachments that may have been maliciously deleted from backups

Patch Information

The vulnerability has been addressed in Tutor LMS version 3.9.5. The fix adds proper capability checks to the delete_existing_user_photo function to ensure only users with appropriate permissions can delete attachments. Detailed code changes can be reviewed in the WordPress Plugin Change Log. Additional vulnerability details are available in the Wordfence Vulnerability Report.

Workarounds

• Temporarily disable the Tutor LMS plugin if immediate patching is not possible
• Restrict user registration to prevent new subscriber accounts until patched
• Implement a custom WordPress filter to add capability checks to the affected function
• Use a security plugin to limit AJAX endpoint access to administrative users only

# Verify current Tutor LMS version
wp plugin list --name=tutor --fields=name,version,status

# Update Tutor LMS to the patched version
wp plugin update tutor

# Check for recent attachment deletions in the database
wp db query "SELECT ID, post_title, post_date FROM wp_posts WHERE post_type='attachment' ORDER BY post_modified DESC LIMIT 20;"