CVE-2026-12900 Spectra Gutenberg Blocks <= 2.19.28 - Authenticated (Contributor+) Stored Cross-Site Scripting via uagb/image Block
Authenticated contributors can inject arbitrary scripts via the image block, leading to stored XSS execution for other users.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-12900?
CVE-2026-12900 is a medium-severity cross-site scripting vulnerability in brainstormforce Spectra Legacy – Gutenberg Blocks, published on 20 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-12900?
How do I fix CVE-2026-12900?
No fix has been published for CVE-2026-12900 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-12900 being exploited?
There is no known exploitation of CVE-2026-12900 in the wild and no public exploit code.
Sources
Also known as GHSA-3rp7-f8f5-j67m.