CVE-2025-11677: Warmcat Libwebsockets

Medium severity, CVSS 6.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Use After Free in WebSocket server implementation in lws_handshake_server in warmcat libwebsockets may allow an attacker, in specific configurations where the user provides a callback function that handles LWS_CALLBACK_HTTP_CONFIRM_UPGRADE, to achieve denial of service.

Affected products

• Warmcat Libwebsockets

Published 2025-10-20. Last modified 2026-10-08.