Medium 5.3Published Apr 20, 2026

CVE-2026-6675Responsive Blocks <= 2.2.0 - Unauthenticated Open Email Relay via REST API 'email_to' Parameter

Updated under an hour ago (Oct 26, 2026, 7:00 PM ET)

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It affects cyberchimps Responsive Blocks – Page Builder for Blocks & Patterns. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for cyberchimps Responsive Blocks – Page Builder for Blocks & Patterns

Exploited in the last 30 days

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.

CVSS: 5.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-20
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Wordfence
NVD analysis: Deferred
Record last updated: Apr 21, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

cyberchimps Responsive Blocks – Page Builder for Blocks & Patterns cyberchimps:responsive_blocks_page_builder_for_blocks_and_patterns (from the name)	through 2.2.0	CNA record

References

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/17452a29-bcef-451a-9893-a436ac5d3b80?source=cve
https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2403
https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2403
https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2212
https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2212
https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2324
https://plugins.trac.wordpress.org/browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2324

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.