CVE-2025-11677 MEDIUM

CVE-2025-11677: Use After Free in libwebsockets WebSocket server

Vendor Warmcat
Product libwebsockets
Weakness CWE-416
Published October 20, 2025
Last update October 24, 2025

CVSS base score

6.3/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

October 20, 2025 CVE published
October 24, 2025 Record updated