CVE-2026-12900: Brainstormforce Spectra Legacy – Gutenberg Blocks

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

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

• Brainstormforce Spectra Legacy – Gutenberg Blocks: up to and including 2.19.28

Published 2026-07-20. Last modified 2026-07-22.