CVE-2026-6675
Responsive Blocks <= 2.2.0 - Unauthenticated Open Email Relay via REST API 'email_to' Parameter
CVSS Score
5.3
EPSS Score
0.0%
EPSS Percentile
0th
The Responsive Blocks – Page Builder for Blocks & Patterns plugin for WordPress is vulnerable to Unauthenticated Open Email Relay in all versions up to, and including, 2.2.0. This is due to insufficient authorization checks and missing server-side validation of the recipient email address supplied via a public REST API route. This makes it possible for unauthenticated attackers to send arbitrary emails to any recipient of their choosing through the affected WordPress site's mail server, effectively turning the site into an open mail relay.
| CWE | CWE-20 |
| Vendor | cyberchimps |
| Product | responsive blocks – page builder for blocks & patterns |
| Published | Apr 21, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
cyberchimps / Responsive Blocks – Page Builder for Blocks & Patterns
0 ≤ 2.2.0
References
wordfence.com: https://www.wordfence.com/threat-intel/vulnerabilities/id/17452a29-bcef-451a-9893-a436ac5d3b80?source=cve plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2403 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2403 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2212 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2212 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2324 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2324
Credits
Even Stokkedalen