CVE-2025-11678

Stack-based Buffer Overflow in libwebsockets DNS response parsing

State: Published
Severity: 7.5 High
Published: Oct 20, 2025
Updated: Oct 20, 2025
Reserved: Oct 13, 2025

Description

Stack-based Buffer Overflow in lws_adns_parse_label in warmcat libwebsockets allows, when the LWS_WITH_SYS_ASYNC_DNS flag is enabled during compilation, to overflow the label_stack, when the attacker is able to sniff a DNS request in order to craft a response with a matching id containing a label longer than the maximum.

Scores

CVSS	Score	Vector	Source
4.0	7.5 High	CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	Nozomi

Weaknesses

CWE-121 Stack-based Buffer Overflow

Affected Products

Product	Versions
libwebsocketwarmcat	4.0 through 4.4.2Affected 4.0 through 4.3.6Affected

References

https://libwebsockets.org/git/libwebsockets/commit?id=2bb9598562b37c942ba5b04bcde3f7fdf66a9d3apatchvendor-advisory
https://www.nozominetworks.com/labs/vulnerability-advisories-cve-2025-11678third-party-advisory

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