# Gutenberg Blocks – PublishPress Blocks Controls, Visibility, Reusable Blocks <= 3.7.6 - Authenticated (Author+) Stored Cross-Site Scripting via Content Display Block Post Text Excerpt

- **ID:** WPSEC-2026-3104
- **Plugin:** PublishPress Blocks – Block Controls, Block Visibility, Block Permissions (`advanced-gutenberg`), https://wordpress.org/plugins/advanced-gutenberg/
- **Affected versions:** all versions before 3.7.7
- **Fixed in:** 3.7.7 (Update to 3.7.7 or later.)
- **Severity:** Medium 6.4 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-79
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-11-13)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/advanced-gutenberg
- **Fix released:** 2026-11-12
- **Published:** 2026-11-13
- **URL:** https://wpsec.com/vuln/WPSEC-2026-3104/

## Description

The PublishPress Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the post text excerpt of the Content Display (Recent Posts) block in all versions up to, and including, 3.7.6. This is due to insufficient output escaping: the advgbExtractHtml() function strips tags from post content and then decodes HTML entities, and the result is printed without escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses a page that shows their published post in a Content Display block.

## References

- https://wpsec.com/vuln/WPSEC-2026-3104/
- https://plugins.svn.wordpress.org/advanced-gutenberg/tags/3.7.7/
- https://wordpress.org/plugins/advanced-gutenberg/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-3104/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.