CVE-2025-11680

Out-of-bounds Write in unfilter_scanline in warmcat libwebsockets allows, when the LWS_WITH_UPNG flag is enabled during compilation and the HTML display stack is used, to write 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 width value that causes an integer overflow which value is used for determining the size of a heap allocation.

CVSS 4.0

5.9CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-25)

CWE

CWE-787

Published

2025-10-20

Modified

2026-10-08

Record from

the NVD, synced 2026-10-19

References

• https://libwebsockets.org/git/libwebsockets/commit?id=2b715249f39291c86443b969a1088d59b6a89b78
• https://www.nozominetworks.com/labs/vulnerability-advisories-cve-2025-11680

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