{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-4658", "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599", "state": "PUBLISHED", "assignerShortName": "Wordfence", "dateReserved": "2026-03-23T15:37:56.964Z", "datePublished": "2026-05-02T04:27:44.707Z", "dateUpdated": "2026-05-02T04:27:44.707Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599", "shortName": "Wordfence", "dateUpdated": "2026-05-02T04:27:44.707Z"}, "affected": [{"vendor": "wpdevteam", "product": "Gutenberg Essential Blocks \u2013 Page Builder for Gutenberg Blocks & Patterns", "versions": [{"version": "0", "status": "affected", "lessThanOrEqual": "6.0.4", "versionType": "semver"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "The Essential Blocks \u2013 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."}], "title": "Gutenberg Essential Blocks <= 6.0.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via Block Attributes", "references": [{"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/3e7eed9d-2d44-4951-b66b-7d8995ca617d?source=cve"}, {"url": "https://plugins.trac.wordpress.org/browser/essential-blocks/trunk/includes/Blocks/AddToCart.php#L118"}, {"url": "https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.0.4/includes/Blocks/AddToCart.php#L118"}, {"url": "https://plugins.trac.wordpress.org/browser/essential-blocks/trunk/includes/Blocks/AddToCart.php#L120"}, {"url": "https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.0.4/includes/Blocks/AddToCart.php#L120"}, {"url": "https://plugins.trac.wordpress.org/browser/essential-blocks/trunk/includes/Blocks/AddToCart.php#L65"}, {"url": "https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.0.4/includes/Blocks/AddToCart.php#L65"}, {"url": "https://plugins.trac.wordpress.org/browser/essential-blocks/trunk/includes/Blocks/AddToCart.php#L66"}, {"url": "https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.0.4/includes/Blocks/AddToCart.php#L66"}, {"url": "https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3516287%40essential-blocks%2Ftags%2F6.1.0%2Fincludes%2FBlocks%2FAddToCart.php&old=3178777%40essential-blocks%2Ftrunk%2Fincludes%2FBlocks%2FAddToCart.php"}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "cweId": "CWE-79", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N", "baseScore": 6.4, "baseSeverity": "MEDIUM"}}], "credits": [{"lang": "en", "type": "finder", "value": "Jack Pas"}, {"lang": "en", "type": "finder", "value": "darkestmode"}], "timeline": [{"time": "2026-03-23T15:53:08.000Z", "lang": "en", "value": "Vendor Notified"}, {"time": "2026-05-01T16:12:21.000Z", "lang": "en", "value": "Disclosed"}]}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "The Essential Blocks \u2013 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."}], "id": "CVE-2026-4658", "lastModified": "2026-05-02T05:16:00.767", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 3.1, "impactScore": 2.7, "source": "security@wordfence.com", "type": "Primary"}]}, "published": "2026-05-02T05:16:00.767", "references": [{"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.0.4/includes/Blocks/AddToCart.php#L118"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.0.4/includes/Blocks/AddToCart.php#L120"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.0.4/includes/Blocks/AddToCart.php#L65"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/essential-blocks/tags/6.0.4/includes/Blocks/AddToCart.php#L66"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/essential-blocks/trunk/includes/Blocks/AddToCart.php#L118"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/essential-blocks/trunk/includes/Blocks/AddToCart.php#L120"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/essential-blocks/trunk/includes/Blocks/AddToCart.php#L65"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/browser/essential-blocks/trunk/includes/Blocks/AddToCart.php#L66"}, {"source": "security@wordfence.com", "url": "https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3516287%40essential-blocks%2Ftags%2F6.1.0%2Fincludes%2FBlocks%2FAddToCart.php&old=3178777%40essential-blocks%2Ftrunk%2Fincludes%2FBlocks%2FAddToCart.php"}, {"source": "security@wordfence.com", "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/3e7eed9d-2d44-4951-b66b-7d8995ca617d?source=cve"}], "sourceIdentifier": "security@wordfence.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "security@wordfence.com", "type": "Primary"}]}

{}

{"created": "2026-05-02T07:00:06.919478+00:00", "updated": "2026-05-02T07:00:06.919494+00:00", "vendors": []}