CVE-2026-83546Network attack vector

Contributor-level stored XSS via unescaped skin attribute

Published Sep 11, 2026 · Updated Sep 11, 2026

Stored XSS in the CoolClock WordPress plugin before 4.3.8 allows remote authenticated users to execute scripts via a crafted skin setting. The plugin inserts the skin value into an HTML class attribute without proper output escaping, so crafted markup becomes executable page content. Contributor-level access is required to save the payload, which runs in the browser of anyone who views the affected content.

CVSS severityUnavailable
Unscored
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in the CoolClock WordPress plugin before 4.3.8 allows remote authenticated users to execute scripts via a crafted skin setting. The plugin inserts the skin value into an HTML class attribute without proper output escaping, so crafted markup becomes executable page content. Contributor-level access is required to save the payload, which runs in the browser of anyone who views the affected content.

The record

CVE
CVE-2026-83546
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
Rolf Allard van Hagen
Product
CoolClock
Classifications
T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <4.3.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Rolf Allard van Hagen · CoolClockversion=0 <4.3.8

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1059.007JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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