CVE-2025-11677

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.

CVSS 4.0

6.3CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 34% of CVEs (scores of 2026-10-25)

CWE

CWE-416

Published

2025-10-20

Modified

2026-10-08

Record from

the NVD, synced 2026-10-19

References

• https://libwebsockets.org/git/libwebsockets/commit?id=2f082ec31261f556969160143ba94875d783971a
• https://www.nozominetworks.com/labs/vulnerability-advisories-cve-2025-11677

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