CVE-2025-11679: Out-of-bounds Read in libwebsockets PNG parsing

Published Oct 20, 2025

Updated

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

Affected Software

1 affected component

warmcat libwebsockets

Remediation

Information

Update the library to its latest stable release, if not possible backport the fix commit 7df24cca7144d7bc9233b6b0a71108bd154ce101

Event History

Oct 20, 2025

CVE Published

via MITRE·01:58 PM

Data Sourced

via MITRE·01:58 PM

RemedyDescriptionWeakness

Data Sourced

via NVD·02:15 PM

DescriptionSeverityWeakness

Frequently Asked Questions

What is the severity of CVE-2025-11679?

CVE-2025-11679 is a high severity vulnerability that allows for an out-of-bounds read in the warmcat libwebsockets.

How do I fix CVE-2025-11679?

To fix CVE-2025-11679, ensure that the LWS_WITH_UPNG flag is not enabled during compilation if you are not using the HTML display stack.

What software is affected by CVE-2025-11679?

CVE-2025-11679 affects warmcat libwebsockets when compiled with the LWS_WITH_UPNG flag enabled.

What can happen if CVE-2025-11679 is exploited?

Exploitation of CVE-2025-11679 can lead to reading past a heap-allocated buffer, potentially causing a crash.

How can CVE-2025-11679 impact users?

Users visiting an attacker-controlled website may experience crashes or disruptions due to CVE-2025-11679.