# CVE-2026-10833: wpdevteam Essential Blocks Stored XSS in configurablePrefix attribute

Source: https://junglewise.ai/threats/cve-2026-10833-wpdevteam-essential-blocks-stored-xss-in-configurableprefix  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-25. Updated: 2026-06-25  
License: CC BY 4.0 with a link back

CVE-2026-10833 · Severity: medium · CVSS 6.4 · Published 2026-06-25

A vulnerability exists in the Essential Blocks plugin for WordPress, which is used to design and build custom website layouts. An attacker with basic contributor-level access can inject malicious scripts into website pages. These scripts will run automatically in the browser of any visitor who views the affected page, potentially leading to unauthorized actions or data theft.

Vendors: [WPDeveloper](https://junglewise.ai/threats/vendors/wpdeveloper).

## Quick answers

**Is CVE-2026-10833 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-10833 being exploited in the wild.

**How severe is CVE-2026-10833?** Medium severity, with a CVSS score of 6.4, published 25 June 2026.

**Which products and versions are affected?** WPDeveloper Essential Blocks – Page Builder for Gutenberg Blocks & Patterns up to, and including, 6.1.4.

**Is there a fix for CVE-2026-10833?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-10833 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-10833?** Check whether you run WPDeveloper Essential Blocks – Page Builder for Gutenberg Blocks & Patterns at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The Essential Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting (XSS) due to insufficient input sanitization and output escaping on the 'configurablePrefix' block attribute. This vulnerability allows authenticated attackers with Contributor-level permissions or higher to inject arbitrary web scripts into pages. The malicious payload is stored on the server and executes in the context of a user's browser session when they visit the compromised page. The issue is present in all versions up to and including 6.1.4. Security engineers should ensure the plugin is updated to a version where these attributes are properly sanitized and escaped.

## Affected products

- wpdevteam Gutenberg Essential Blocks – Page Builder for Gutenberg Blocks & Patterns up to, and including, 6.1.4

## Timeline

- 2026-06-25: disclosed: CVE published by Wordfence and NVD

## References

- [https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.1.4/includes/Blocks/TableOfContents.php](https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.1.4/includes/Blocks/TableOfContents.php)
- [https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.1.4/includes/Blocks/TableOfContents.php](https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.1.4/includes/Blocks/TableOfContents.php)
- [https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.1.4/src/blocks/table-of-contents/src/frontend.js](https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.1.4/src/blocks/table-of-contents/src/frontend.js)
- [https://www.wordfence.com/threat-intel/vulnerabilities/id/0efe8bbd-c1c9-48ed-adab-34c0ac3da8bf?source=cve](https://www.wordfence.com/threat-intel/vulnerabilities/id/0efe8bbd-c1c9-48ed-adab-34c0ac3da8bf?source=cve)