What the vulnerability does
01Description
The Spectra Gutenberg Blocks – Website Builder for the Block Editor plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 2.19.25. This makes it possible for authenticated attackers, with Contributor-level access and above, to execute code on the server. Exploitation requires a two-block payload embedded in post content: the first block registers a fake uagb/-prefixed block type with an attacker-specified render_callback, and the second block of the same fake type triggers invocation of that callback via call_user_func() during sequential block rendering in the same page request.
Explanation of Vulnerability in Simple Terms
02Summary
Spectra Gutenberg Blocks versions up to 2.19.25 contain a privilege management flaw that allows authenticated users with low-level permissions to gain unauthorized access to sensitive functions. An attacker with a basic user account can read, modify, or delete site data without proper authorization. Update to a version newer than 2.19.25 immediately.
What an attacker can do
03Attacker Capabilities
Read, modify, or delete site data and settings without proper authorization.
Potential impact on your site
04Site Impact
Unauthorized users can compromise site content, settings, and data integrity from within their account.
Conditions required to exploit
05Prerequisites
Attacker must have a low-privilege user account on the site (e.g., subscriber or contributor role).
Key dates
06Disclosure timeline
May 30, 2026
CVE published
June 1, 2026
Record updated
