A critical authorization bypass vulnerability in FreshRSS allows unauthenticated attackers to access private user feeds, posing a significant risk to data privacy.

The application fails to properly enforce access controls on master authentication tokens, allowing an unauthenticated attacker to bypass existing restrictions and view private content intended only for authorized users.

The vulnerability carries a CVSS score of 7.5, reflecting its high potential for unauthorized data exposure. Successful exploitation allows an attacker to access private RSS feeds, which may contain sensitive information, potentially leading to unauthorized data disclosure and a breach of user privacy.

Immediate Action: Upgrade to FreshRSS version 1.28.0 or later to apply the security fix for the authentication logic.

Proactive Monitoring: Review web server access logs for anomalous requests to feed endpoints or unauthorized attempts to access restricted user data.

Compensating Controls: Ensure the application is behind a robust Web Application Firewall (WAF) and verify that anonymous viewing settings are configured correctly until the update is applied.

Public Exploit Available: Unknown.

Given the ease of exploitation and the potential for unauthorized access to private data, administrators should prioritize updating their FreshRSS instances to version 1.28.0 immediately. Regular audits of access controls and monitoring for unauthorized traffic patterns are essential to maintain the security posture of the platform.