Vulnerability · Published Apr 22, 2026 · Assigned by Wordfence
CVE-2026-4125WPMK Block <= 1.0.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
Medium 6.4
In plain English
A medium-severity cross-site scripting in WPMK Block from wpmkorg. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 21% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| wpmkorg | WPMK Block | 0 – through 1.0.1 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
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