CVE-2025-11679 | Nozomi Networks Labs

Summary

Out-of-bounds Read in lws_upng_emit_next_line in warmcat libwebsockets.

Impact

It 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.

Issue Date

October 8, 2025

Affects

This issue affects libwebsockets from (including) 4 and up to (including) 4.3.6, 4.4.2

CVE Name

CVE-2025-11679

CVSS Details

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS Score

5.9

Solution

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

Mitigations

Acknowledgements

Raffaele Bova of Nozomi Networks

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