XSS in Coolclock

CVE-2026-83546

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (37.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 37.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-83546: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

  • Coolclock

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-83546?
CVE-2026-83546 is a medium-severity vulnerability in Coolclock, classified under Cross-site Scripting. CVSS score: 6.8/10. Published 2026-09-11.
How severe is CVE-2026-83546?
Medium severity. CVSS v3 base score is 6.8 out of 10.