---
id: CVE-2025-11677
title: "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_UPGRA…"
summary: "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_UPGRA…"
severity: none
cwe:
  - CWE-416
published: '2025-10-20'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T22:10:00.563'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-11677'
references:
  - url: >-
      https://libwebsockets.org/git/libwebsockets/commit?id=2f082ec31261f556969160143ba94875d783971a
    label: prodsec@nozominetworks.com
  - url: >-
      https://www.nozominetworks.com/labs/vulnerability-advisories-cve-2025-11677
    label: prodsec@nozominetworks.com
tags:
  - nvd
epss: 0.00405
epssPercentile: 0.32593
ingestedAt: '2026-10-08T22:11:53.816Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.