CVE-2025-11679

Out-of-bounds Read in libwebsockets PNG parsing

5.9 Medium

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: Active

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

0.39%Up 0.4 points since Oct 21, 2025

What each source reports

CVE List Score used 5.9

Out-of-bounds Read in libwebsockets PNG parsing

Record: CVE-2025-11679
CVSS 4.0: 5.9 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness: CWE-125
Updated: 2026-11-02

EUVDEUVD-2025-35056 5.9

Record: EUVD-2025-35056
CVSS 4.0: 5.9 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-q5q2-4x99-gg9p 5.9

Out-of-bounds Read in lws_upng_emit_next_line in warmcat libwebsockets allows, when the...

Record: GHSA-q5q2-4x99-gg9p
CVSS 4.0: 5.9 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness: CWE-125
Updated: 2026-11-02

NVD 5.9

Record: CVE-2025-11679
CVSS 4.0: 5.9 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness: CWE-125
Updated: 2026-11-02

OSVDEBIAN-CVE-2025-11679 5.9

Record: DEBIAN-CVE-2025-11679
CVSS 4.0: 5.9 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Updated: 2026-11-02

OSVUBUNTU-CVE-2025-11679 5.9

Record: UBUNTU-CVE-2025-11679
CVSS 4.0: 5.9 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

Affected products

warmcat libwebsockets

History

History
Recorded	Changed	Sources
Nov 3, 2026	affected
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2025-11679 is a medium vulnerability (CVSS 5.9) in Warmcat Libwebsockets, published October 20, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.39%, the 33rd percentile. No source names a fixed version.