WebFeed is a lightweight web feed reader extension for Firefox/Chrome. Multiple HTML injection vulnerabilities in WebFeed can lead to CSRF and UI spoofing attacks. A remote attacker can provide malicious RSS feeds and attract the victim user to visit it using WebFeed. The attacker can then inject malicious HTML into the extension page and fool the victim into sending out HTTP requests to arbitrary sites with the victim's credentials. Users are vulnerable to CSRF attacks when visiting malicious RSS feeds via WebFeed. Unwanted actions could be executed on the user's behalf on arbitrary websites. This issue has been addressed in release version 0.9.2. All users are advised to upgrade. There are no known workarounds for this vulnerability.