CVE-2025-11680 MEDIUM

CVE-2025-11680: Out-of-bounds Write in libwebsockets PNG parsing

Vendor Warmcat
Product libwebsockets
Weakness CWE-787
Published October 20, 2025
Last update October 20, 2025

CVSS base score

5.9/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

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

What the vulnerability does

01Description

Out-of-bounds Write in unfilter_scanline in warmcat libwebsockets allows, when the LWS_WITH_UPNG flag is enabled during compilation and the HTML display stack is used, to write past a heap allocated buffer possibly causing a crash, when the user visits an attacker controlled website that contains a crafted PNG file with a big width value that causes an integer overflow which value is used for determining the size of a heap allocation.

Key dates

02Disclosure timeline

October 20, 2025 CVE published
October 20, 2025 Record updated