Description
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.
Published: 2026-04-21
Score: 5.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Unauthenticated Open Email Relay
Action: Patch
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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History

Wed, 22 Apr 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Cyberchimps
Cyberchimps responsive Blocks – Page Builder For Blocks & Patterns
Wordpress
Wordpress wordpress
Vendors & Products Cyberchimps
Cyberchimps responsive Blocks – Page Builder For Blocks & Patterns
Wordpress
Wordpress wordpress

Tue, 21 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 21 Apr 2026 02:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Responsive Blocks <= 2.2.0 - Unauthenticated Open Email Relay via REST API 'email_to' Parameter
Weaknesses CWE-20
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}


Subscriptions

Cyberchimps Responsive Blocks – Page Builder For Blocks & Patterns
Wordpress Wordpress
cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published:

Updated: 2026-04-21T13:22:00.182Z

Reserved: 2026-04-20T14:13:26.851Z

Link: CVE-2026-6675

cve-icon Vulnrichment

Updated: 2026-04-21T13:21:56.653Z

cve-icon NVD

Status : Deferred

Published: 2026-04-21T03:16:09.210

Modified: 2026-04-22T20:22:50.570

Link: CVE-2026-6675

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-22T11:46:52Z

Weaknesses