CVE-2026-96256: Gutenberg Essential Blocks <= 6.4.5 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'marker' Attribute
The Gutenberg Essential Blocks – Page Builder for Gutenberg Blocks & Patterns plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Google Map block's 'marker' attribute in versions up to, and including, 6.4.5 This is due to insufficient input sanitization and output escaping on marker title/content values, which are stored as JSON and then decoded and concatenated directly into raw HTML by the frontend script's InfoWindow content builder. 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 Software
Event History
Frequently Asked Questions
Who can exploit this issue?
An attacker needs an authenticated WordPress account with Contributor-level access or higher. No user interaction by the attacker is required once they can submit the malicious marker data.
Who is exposed to the injected script?
Any user who accesses a page containing the attacker-injected Google Map block may execute the stored script in their browser. The vulnerable frontend InfoWindow content builder renders the affected marker title or content as raw HTML.
How can I determine whether my site is affected?
Sites running Gutenberg Essential Blocks version 6.4.5 or earlier are affected. Review pages using the Google Map block, particularly marker title and content values stored in the block's JSON data, for unexpected HTML or script content.