---
id: CVE-2025-11680
title: >-
  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 …
summary: >-
  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 …
severity: none
cwe:
  - CWE-787
published: '2025-10-20'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T23:10:00.237'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-11680'
references:
  - url: >-
      https://libwebsockets.org/git/libwebsockets/commit?id=2b715249f39291c86443b969a1088d59b6a89b78
    label: prodsec@nozominetworks.com
  - url: >-
      https://www.nozominetworks.com/labs/vulnerability-advisories-cve-2025-11680
    label: prodsec@nozominetworks.com
tags:
  - nvd
epss: 0.00394
epssPercentile: 0.31102
ingestedAt: '2026-09-30T23:29:32.435Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.