CVE-2026-15565 [HIGH] – A flaw was found in Undertow. A remote attacker can cause Out of Memory on websockets endp

A flaw was found in Undertow. A remote attacker can cause Out of Memory on websockets endpoint without authentication on any @ServerEndpoint class that has any @OnMessage method. This allows an attacker to cause Denial of Service attack without authentication and using only a standard WebSocket handshake.