Vulnerability · Published May 2, 2026 · Assigned by Wordfence

CVE-2026-4658Gutenberg Essential Blocks <= 6.0.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via Block Attributes

Medium 6.4

In plain English

A medium-severity cross-site scripting in Gutenberg Essential Blocks – Page Builder for Gutenberg Blocks & Patterns from wpdevteam. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities).

Severity (CVSS 3.1)6.4Medium

Exploit odds (30 days)0.4%top 63.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

The Essential Blocks – Page Builder Gutenberg Blocks, Patterns & Templates plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the className, classHook, and blockId attributes in the Add to Cart block (essential-blocks/add-to-cart) in all versions up to, and including, 6.0.4. This is due to insufficient output escaping in the render_callback() function where these attributes are placed into class and data-id HTML attributes using raw sprintf() and implode() without esc_attr() escaping. While the outer wrapper div uses get_block_wrapper_attributes() which properly escapes, the inner divs do not. 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 (as reported)

Vendor	Product	Versions
wpdevteam	Gutenberg Essential Blocks – Page Builder for Gutenberg Blocks & Patterns	0 – through 6.0.4

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

In plain English

Official description

Affected products (as reported)

References