Stack-based Buffer Overflow Affecting libwebsockets package, versions <4.3.5-1+deb13u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.29% (22nd percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ECHOLATEST-LIBWEBSOCKETS-19256848
  • published25 Aug 2026
  • disclosed20 Oct 2025

Introduced: 20 Oct 2025

CVE-2025-11678  (opens in a new tab)
CWE-121  (opens in a new tab)

How to fix?

Upgrade Echo:latest libwebsockets to version 4.3.5-1+deb13u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libwebsockets package and not the libwebsockets package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1