warmcat libwebsockets up to 4.3.6/4.4.2 PNG File Parser lws_upng_emit_next_line out-of-bounds

Summaryinfo

A vulnerability classified as problematic has been found in warmcat libwebsockets up to 4.3.6/4.4.2. This impacts the function lws_upng_emit_next_line of the component PNG File Parser. This manipulation causes out-of-bounds. This vulnerability is handled as CVE-2025-11679. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability classified as problematic was found in warmcat libwebsockets up to 4.3.6/4.4.2. Affected by this vulnerability is the function lws_upng_emit_next_line of the component PNG File Parser. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, and availability. The summary by CVE is:

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.

The weakness was released by Raffaele Bova. The advisory is shared at libwebsockets.org. This vulnerability is known as CVE-2025-11679 since 10/13/2025. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 271670 (Linux Distros Unpatched Vulnerability : CVE-2025-11679), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (271670) and EUVD (EUVD-2025-35056). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• warmcat

Name

• libwebsockets

Version

• 4.3.0
• 4.3.1
• 4.3.2
• 4.3.3
• 4.3.4
• 4.3.5
• 4.3.6
• 4.4.0
• 4.4.1
• 4.4.2

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

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• 🔒
• 🔒

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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