CVE-2026-4658
Medium · 6.4CVSS
6.4
EPSS
0.4%
Published
May 2, 2026
CISA due date
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The record
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 packages
| Ecosystem | Package | Introduced | Fixed |
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Related vulnerabilities
- CVE-2026-96379 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96382 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96368 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96361 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96362 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96360 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96357 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79
- CVE-2026-96358 Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting")… CWE-79