PT-2026-33914 · Cyberchimps · Responsive Blocks – Page Builder For Blocks & Patterns

Even Stokkedalen · Published 2026-04-21 · Updated 2026-04-21 · CVE-2026-6675

Mitre

CVSS v3.1

5.3

Medium

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

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.

Fix

RCE

Weakness Enumeration

CWE-20

Related Identifiers

CVE-2026-6675

Affected Products

Responsive Blocks – Page Builder For Blocks & Patterns

References · 8

• https://nvd.nist.gov/vuln/detail/CVE-2026-6675 · Security Note
• https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2212 · Note
• https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2403 · Note
• https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2324 · Note
• https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2324 · Note
• https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2403 · Note
• https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2212 · Note
• https://wordfence.com/threat-intel/vulnerabilities/id/17452a29-bcef-451a-9893-a436ac5d3b80?source=cve · Note