Use-after-free in libwebsockets - CVE-2025-11677

Vulnerability identifier: #VU117947

CSH Severity: Medium

CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-11677

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service attack.

The vulnerability exists due to a use-after-free error within the lws_handshake_server() function in lib/roles/http/server/server.c. A remote attacker can send specially crafted data to the application and perform a denial of service attack.

libwebsockets
openEuler
Ubuntu
libwebsockets (Ubuntu package)
libwebsockets
libwebsockets-debuginfo
libwebsockets-debugsource
libwebsockets-devel
libwebsockets-help

Install updates from vendor's website.

libwebsockets (Ubuntu package) - addressed in versions 3.2.1-3ubuntu0.1~esm1, 4.0.20-2ubuntu1.1, 4.3.3-1.1ubuntu0.1~esm1
libwebsockets - update to 4.3.0-7
libwebsockets-debuginfo - update to 4.3.0-7
libwebsockets-debugsource - update to 4.3.0-7
libwebsockets-devel - update to 4.3.0-7
libwebsockets-help - update to 4.3.0-7

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

• Multiple vulnerabilities in libwebsockets
• openEuler update for libwebsockets
• Ubuntu update for libwebsockets