CoolClock permits contributor stored XSS in inline scripts
CoolClock before 4.3.8 outputs an attacker-controlled custom skin setting inside an inline script without adequate escaping. A Contributor or higher role can store arbitrary JavaScript that executes when the affected content is viewed. The authoritative export does not name the setting, save action, or rendering function.
- Component
- CoolClock
- Plugin slug
coolclock- Affected
- < 4.3.8
- Safe version
4.3.8- Published
- Sep 11, 2026
This CVE was published Sep 11, 2026 and is one of 3 known issues for this plugin.
Update, patch or deactivate.
Update CoolClock to 4.3.8 or later. The authoritative export marks versions below 4.3.8 affected. The application-level fix must reject untrusted executable input and safely encode retained values for their exact JavaScript context.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
The CoolClock WordPress plugin before 4.3.8 does not properly escape a custom skin setting before outputting it inside an inline script, allowing users with contributor-level access and above to inject arbitrary JavaScript that executes when the content is viewed.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H