CVE-2025-15021Network attack vector

Stored XSS via unsanitized plugin settings

Published Jan 14, 2026 · Updated Jan 14, 2026

Stored XSS in Kapsule Corp Gotham Block Extra Light 1.5.0 and earlier allows remote authenticated users to inject scripts via admin settings. The plugin saves insufficiently sanitized setting values and renders them in its configurable ad-block popup without context-appropriate output escaping. Administrator-level access is required, and exploitation is limited to multisite installations or sites where unfiltered_html is disabled; injected scripts run when a user loads affected content.

CVSS severity4.4
Medium
EPSS probability0.22%
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 Kapsule Corp Gotham Block Extra Light 1.5.0 and earlier allows remote authenticated users to inject scripts via admin settings. The plugin saves insufficiently sanitized setting values and renders them in its configurable ad-block popup without context-appropriate output escaping. Administrator-level access is required, and exploitation is limited to multisite installations or sites where unfiltered_html is disabled; injected scripts run when a user loads affected content.

The record

CVE
CVE-2025-15021
Published
Jan 14, 2026
Updated
Jan 14, 2026
Vendor
Kapsule Corp
Product
Gotham Block Extra Light
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jan 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 14, 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=* <=1.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Kapsule Corp · Gotham Block Extra Lightversion=* <=1.5.0

Published CVSS scores

4.4WordfenceCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

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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