---
id: CVE-2025-11679
title: >-
  Out-of-bounds Read in lws_upng_emit_next_line in warmcat libwebsockets allows,
  when the LWS_WITH_UPNG flag is enabled during compilation and the HTML display
  stack is used, to read past a heap allocated buffer possibly causing a crash,
  w…
summary: >-
  Out-of-bounds Read in lws_upng_emit_next_line in warmcat libwebsockets allows,
  when the LWS_WITH_UPNG flag is enabled during compilation and the HTML display
  stack is used, to read past a heap allocated buffer possibly causing a crash,
  w…
severity: none
cwe:
  - CWE-125
published: '2025-10-20'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T22:10:00.563'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-11679'
references:
  - url: >-
      https://libwebsockets.org/git/libwebsockets/commit?id=7df24cca7144d7bc9233b6b0a71108bd154ce101
    label: prodsec@nozominetworks.com
  - url: >-
      https://www.nozominetworks.com/labs/vulnerability-advisories-cve-2025-11679
    label: prodsec@nozominetworks.com
tags:
  - nvd
epss: 0.00394
epssPercentile: 0.31433
ingestedAt: '2026-10-08T22:11:53.817Z'
---

## Overview

Out-of-bounds Read in lws_upng_emit_next_line in warmcat libwebsockets allows, when the LWS_WITH_UPNG flag is enabled during compilation and the HTML display stack is used, to read 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 height dimension.

## Remediation

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