CVE-2026-4125: Wpmkorg Wpmk Block

Medium severity, CVSS 6.4. EPSS: 0.3% chance of exploitation in the next 30 days.

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

• Wpmkorg Wpmk Block: up to and including 1.0.1

Published 2026-04-22. Last modified 2026-06-17.