Stack-based Buffer Overflow Affecting libwebsockets package, versions <4.3.3-1.1ubuntu0.1~esm1


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.29% (22nd percentile)

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  • Snyk IDSNYK-UBUNTU2404-LIBWEBSOCKETS-13653346
  • published26 Feb 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 Ubuntu:24.04 libwebsockets to version 4.3.3-1.1ubuntu0.1~esm1 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 Ubuntu. See How to fix? for Ubuntu:24.04 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