EEF-CVE-2026-56811 Phoenix transports do not limit channel joins per connection, enabling process-exhaustion denial of service

Summary Allocation of Resources Without Limits or Throttling vulnerability in phoenixframework phoenix Phoenix.Socket module allows an unauthenticated attacker to cause a denial of service against any endpoint that mounts a Phoenix socket with a reachable channel transport WebSocket or LongPoll...

CVE-2026-56811 Phoenix transports do not limit channel joins per connection, enabling process-exhaustion denial of service

Allocation of Resources Without Limits or Throttling vulnerability in phoenixframework phoenix Phoenix.Socket module allows an unauthenticated attacker to cause a denial of service against any endpoint that mounts a Phoenix socket with a reachable channel transport WebSocket or LongPoll. This...

CVE-2026-56811

The CVE-2026-56811 issue affects the Phoenix framework (Phoenix.Socket) where transports (WebSocket/LongPoll) allow an unbounded number of channel joins per transport, enabling a single unauthenticated client to exhaust BEAM processes and cause a denial-of-service across the node. Root cause is l...