EUVD-2026-42050

Phoenix: Presence keys colliding with Object.prototype members break existence checks...

Denial Of Service (DoS)

Phoenix is vulnerable to Denial-of-Service DoS. The vulnerability is due to an unsafe truthiness check for attacker-controlled presence keys that can reference JavaScript Object.prototype properties, which allows an attacker to trigger uncaught exceptions and cause persistent client-side denial o...

CVE-2026-56812

Improper Check for Unusual or Exceptional Conditions vulnerability in phoenixframework phoenix Presence JavaScript client allows an attacker with ordinary channel access to cause a persistent client-side denial of service against every viewer of a presence channel topic. This vulnerability is...

CVE-2026-56812 Phoenix JavaScript presence client crashes on presence keys colliding with Object.prototype members in Presence.syncState/syncDiff

Improper Check for Unusual or Exceptional Conditions vulnerability in phoenixframework phoenix Presence JavaScript client allows an attacker with ordinary channel access to cause a persistent client-side denial of service against every viewer of a presence channel topic. This vulnerability is...