CVE-2025-11680 Out-of-bounds Write in libwebsockets PNG parsing
An attacker can cause a crash via heap buffer overflow in libwebsockets when visiting a malicious site with a crafted PNG, requiring specific compilation flags.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-11680?
CVE-2025-11680 is a medium-severity memory corruption vulnerability in warmcat libwebsockets, published on 20 Oct 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
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.
Weakness: CWE-787
Which versions are affected by CVE-2025-11680?
How do I fix CVE-2025-11680?
No fix has been published for CVE-2025-11680 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-11680 being exploited?
There is no known exploitation of CVE-2025-11680 in the wild and no public exploit code.
Sources
Also known as GHSA-7h7w-vjr9-r6m8.