Unrated severityNVD Advisory· Published Jul 20, 2026· Updated Jul 22, 2026
Spectra Gutenberg Blocks <= 2.19.28 - Authenticated (Contributor+) Stored Cross-Site Scripting via uagb/image Block
CVE-2026-12900
Description
The Spectra Gutenberg Blocks – Website Builder for the Block Editor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the uagb/image block in all versions up to, and including, 2.19.28 due to insufficient input sanitization and output escaping. 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
1- Range: <=2.19.28
Patches
Vulnerability mechanics
References
3- plugins.trac.wordpress.org/browser/ultimate-addons-for-gutenberg/tags/2.19.28/blocks-config/image/class-uagb-image.phpmitre
- plugins.trac.wordpress.org/browser/ultimate-addons-for-gutenberg/tags/2.19.28/includes/blocks/image/block.phpmitre
- www.wordfence.com/threat-intel/vulnerabilities/id/0e9dc5e3-9d72-4c04-8ba9-56428a6fddddmitre
News mentions
1- Wordfence Intelligence Weekly WordPress Vulnerability Report (July 20, 2026 to July 26, 2026)Wordfence Blog · Jul 30, 2026