CVE-2026-83546 CoolClock < 4.3.8 - Contributor+ Stored XSS via Skin Class Attribute
Contributors can inject arbitrary scripts via the skin class attribute in CoolClock, leading to stored XSS when content is viewed.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-83546?
CVE-2026-83546 is a medium-severity cross-site scripting vulnerability in Unknown CoolClock, published on 11 Sep 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
The CoolClock WordPress plugin before 4.3.8 does not properly escape a skin setting before outputting it within an HTML attribute, allowing users with contributor-level access and above to inject arbitrary web scripts that execute when the content is viewed.
Weakness: CWE-79
Which versions are affected by CVE-2026-83546?
How do I fix CVE-2026-83546?
No fix has been published for CVE-2026-83546 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-83546 being exploited?
There is no known exploitation of CVE-2026-83546 in the wild and no public exploit code.
Sources
Also known as GHSA-mvvr-5rcc-xqpx.