CVE-2026-4125
WPMK Block <= 1.0.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
- State
- Published
- Severity
- 6.4 Medium
- Published
- Apr 22, 2026
- Updated
- Apr 22, 2026
- Reserved
- Mar 13, 2026
Description
The WPMK Block plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'class' shortcode attribute in all versions up to and including 1.0.1. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes. Specifically, in the wpmk_block_shortcode() function, the 'class' attribute is extracted from user-controllable shortcode attributes and directly concatenated into an HTML div element's class attribute without any escaping (e.g., esc_attr()). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.4 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N | Wordfence |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
WPMK Blockwpmkorg |
|
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/5e397c7a-2aef-4c23-a224-e324ea4bb4b1?source=cve
- https://plugins.trac.wordpress.org/browser/wpmk-block/trunk/classes/wpmk-block-class.php#L97
- https://plugins.trac.wordpress.org/browser/wpmk-block/tags/1.0.1/classes/wpmk-block-class.php#L97
- https://plugins.trac.wordpress.org/browser/wpmk-block/trunk/classes/wpmk-block-class.php#L82
- https://plugins.trac.wordpress.org/browser/wpmk-block/tags/1.0.1/classes/wpmk-block-class.php#L82
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