Vulnerability · Published Oct 20, 2025 · Assigned by Nozomi
CVE-2025-11680Out-of-bounds Write in libwebsockets PNG parsing
Medium 5.9
In plain English
A medium-severity out-of-bounds write in libwebsockets from warmcat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libwebsockets | no fix listed | DEBIAN-CVE-2025-11680 |
| Debian:13 | libwebsockets | no fix listed | DEBIAN-CVE-2025-11680 |
| Debian:14 | libwebsockets | no fix listed | DEBIAN-CVE-2025-11680 |
| Ubuntu:22.04:LTS | libwebsockets | no fix listed | UBUNTU-CVE-2025-11680 |
| Ubuntu:24.04:LTS | libwebsockets | no fix listed | UBUNTU-CVE-2025-11680 |
| Ubuntu:25.10 | libwebsockets | no fix listed | UBUNTU-CVE-2025-11680 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| warmcat | libwebsockets | 4.0 – through 4.4.24.0 – through 4.3.6 |
Weakness: CWE-787 · Vector: 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
References
- https://libwebsockets.org/git/libwebsockets/commit?id=2b715249f39291c86443b969a1088d59b6a89b78 patch, vendor-advisory
- https://www.nozominetworks.com/labs/vulnerability-advisories-cve-2025-11680 third-party-advisory