CVE-2025-11677
Publication date 20 October 2025
Last updated 10 July 2026
Ubuntu priority
Description
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.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| libwebsockets | 26.04 LTS resolute |
Not affected
|
| 24.04 LTS noble |
Fixed 4.3.3-1.1ubuntu0.1~esm1
|
|
| 22.04 LTS jammy |
Fixed 4.0.20-2ubuntu1.1
|
|
| 20.04 LTS focal |
Fixed 3.2.1-3ubuntu0.1~esm1
|
|
| 18.04 LTS bionic |
Not affected
|
|
| 16.04 LTS xenial |
Not affected
|
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CVSS version: CVSS v4.0
Base score
6.3 · Medium
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
References
Related Ubuntu Security Notices (USN)
- USN-8024-1
- Libwebsockets vulnerabilities
- 11 February 2026