CVE-2026-83545

CoolClock < 4.3.8 - Contributor+ Stored XSS via Custom Skin JSON

Published Sep 11, 2026 CVSS 3.1 · 6.8 Medium EPSS < 1% KEV · Not listed
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.

Analysis

AI-generated

Technical impact

CoolClock WordPress plugin improperly escapes a custom skin setting before embedding it inside an inline script, allowing users with contributor‑level access or higher to inject arbitrary JavaScript that executes when a page is viewed. This stored cross‑site scripting flaw permits malicious code to persist in the site and run in the browsers of all users who view the affected content.

Affected Systems

The vulnerability affects all installations of the CoolClock plugin on WordPress sites that permit custom skin configuration, for any version other vendors or products are listed.

Risk and Exploitability

Exploitation requires an authenticated account with contributor‑level access or higher. Once injected, the malicious script is stored within the custom skin configuration and will execute every time a visitor loads a page that includes the affected skin. The CVSS base score is 6.8, and the vulnerability is not listed in KEV. Because the stored JavaScript can run in the browsers of all visitors, the potential impact is significant if the site is publicly accessible.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update the CoolClock plugin to version 4.3.8 or later through the WordPress dashboard or by installing the latest release from the plugin repository.
  • If an upgrade is not immediately possible, restrict contributor and lower‑privilege accounts from editing custom skin settings, or remove those users from the site until the patch is applied.
  • As a temporary workaround, disable the custom skin feature or deactivate the plugin entirely until an updated version is available.

Generated by OpenCVE AI on September 11, 2026 at 14:18 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 6.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Weaknesses CWE-79
Type Values Removed Values Added
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.
Title CoolClock < 4.3.8 - Contributor+ Stored XSS via Custom Skin JSON
References

Subscriptions

No data.

Weaknesses
  • CWE-79

    Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Sources

Status
PUBLISHED
Assigner
WPScan
Published
Updated
Sep 11, 2026, 10:12 AM
Reserved
Aug 31, 2026, 6:05 PM
Status
Deferred
Published
Sep 11, 2026, 7:16 AM
Modified
Sep 11, 2026, 5:35 PM