CVE-2026-33214: Weblate Auth Bypass Vulnerability

CVE-2026-33214 Overview

CVE-2026-33214 is a Missing Authorization vulnerability (CWE-862) affecting Weblate, a web-based localization tool. In versions prior to 5.17, the translation memory API exposed unintended endpoints that failed to enforce proper access control. This vulnerability allows authenticated users with low privileges to access and potentially modify translation memory data they should not have permission to interact with.

Critical Impact

Authenticated attackers can exploit improperly secured API endpoints to access or manipulate translation memory data without proper authorization checks, potentially compromising the integrity of localization projects.

Affected Products

• Weblate versions prior to 5.17

Discovery Timeline

• 2026-04-15 - CVE CVE-2026-33214 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2026-33214

Vulnerability Analysis

This vulnerability stems from a Missing Authorization flaw (CWE-862) in Weblate's translation memory API implementation. The translation memory feature, designed to store and reuse previously translated content, exposed API endpoints that lacked proper authorization checks. As a result, authenticated users could access translation memory functionality regardless of their actual permissions within the application.

The vulnerability affects the /api/memory/ endpoint, which provides programmatic access to translation memory resources. While the endpoint requires authentication, it fails to validate whether the authenticated user has the appropriate permissions to perform the requested operations on specific translation memory entries.

Root Cause

The root cause is the absence of proper access control enforcement on the translation memory API endpoints. The implementation exposed API routes that were intended for internal use or administrative access without implementing the necessary permission checks. This allowed any authenticated user to interact with translation memory data across projects they may not have legitimate access to.

Attack Vector

The attack vector is network-based and requires low-privilege authenticated access to the Weblate instance. An attacker with a valid user account can send HTTP requests to the /api/memory/ endpoint to interact with translation memory entries. The low attack complexity means no special conditions or additional preparation is required beyond having valid credentials.

The vulnerability allows unauthorized read and write operations on translation memory data, potentially enabling attackers to:

• Access confidential translation content from other projects
• Modify translation memory entries to inject malicious or incorrect translations
• Corrupt translation data integrity across the platform

For detailed technical information about this vulnerability, refer to the GitHub Security Advisory GHSA-mpf5-3vph-q75r and the associated pull request implementing the fix.

Detection Methods for CVE-2026-33214

Indicators of Compromise

• Unusual or unauthorized API requests to /api/memory/ endpoints from unexpected user accounts
• Access logs showing translation memory API calls from users without appropriate project permissions
• Unexpected modifications to translation memory entries or content
• Anomalous patterns of API usage targeting translation memory resources

Detection Strategies

• Monitor web server access logs for requests to /api/memory/ endpoints and correlate with user permission levels
• Implement API request logging and alerting for translation memory endpoint access
• Review application audit logs for translation memory operations performed by users without corresponding project access
• Deploy web application firewall (WAF) rules to monitor and alert on suspicious API patterns

Monitoring Recommendations

• Enable detailed access logging on the Weblate application and web server layer
• Set up alerts for high-volume or unusual API requests targeting translation memory endpoints
• Regularly audit user permissions and compare against translation memory access patterns
• Implement rate limiting on API endpoints to detect and prevent automated exploitation attempts

How to Mitigate CVE-2026-33214

Immediate Actions Required

• Upgrade Weblate to version 5.17 or later immediately to receive the security fix
• If immediate upgrade is not possible, implement the HTTP server workaround to block access to /api/memory/
• Audit existing translation memory data for any unauthorized modifications
• Review access logs to identify potential exploitation attempts

Patch Information

The vulnerability has been fixed in Weblate version 5.17. The fix implements proper access control checks on the translation memory API endpoints to ensure users can only access resources they have explicit permission to interact with. Review the GitHub pull request #18513 for implementation details of the security fix.

Organizations should prioritize upgrading to the patched version as the primary mitigation strategy. The GitHub Security Advisory provides additional context and guidance.

Workarounds

• Block access to /api/memory/ at the HTTP server level (nginx, Apache) to disable the vulnerable functionality
• Implement network-level access controls to restrict API access to trusted sources
• Consider temporarily disabling the translation memory feature if it is not critical to operations
• Use a reverse proxy to filter and block requests to the affected endpoint

# Nginx configuration to block access to translation memory API
location /api/memory/ {
    deny all;
    return 403;
}

# Apache configuration alternative
<Location "/api/memory/">
    Require all denied
</Location>