CVE-2026-6675: CWE-20 Improper Input Validation in cyberchimps Responsive Blocks – Page Builder for Blocks & Patterns
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.
AI Analysis
Technical Summary
CVE-2026-6675 describes an unauthenticated open email relay vulnerability in the Responsive Blocks – Page Builder for Blocks & Patterns WordPress plugin (up to version 2.2.0). The issue arises from insufficient authorization and missing server-side validation of recipient email addresses supplied via a public REST API route. This allows unauthenticated attackers to send arbitrary emails through the WordPress site's mail server, potentially facilitating spam or abuse. The vulnerability is categorized under CWE-20 (Improper Input Validation) and has a medium CVSS score of 5.3. No patch or official remediation has been published as of the vulnerability disclosure date.
Potential Impact
The vulnerability allows unauthenticated attackers to use the affected WordPress site as an open mail relay to send arbitrary emails to any recipient. This can lead to abuse such as spam distribution or reputation damage to the hosting domain. There is no direct impact on confidentiality or availability reported. No known exploits in the wild have been documented.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider disabling or restricting access to the vulnerable REST API endpoint if possible. Monitor for updates from the plugin vendor and apply any official patches promptly once available.
CVE-2026-6675: CWE-20 Improper Input Validation in cyberchimps Responsive Blocks – Page Builder for Blocks & Patterns
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-6675 describes an unauthenticated open email relay vulnerability in the Responsive Blocks – Page Builder for Blocks & Patterns WordPress plugin (up to version 2.2.0). The issue arises from insufficient authorization and missing server-side validation of recipient email addresses supplied via a public REST API route. This allows unauthenticated attackers to send arbitrary emails through the WordPress site's mail server, potentially facilitating spam or abuse. The vulnerability is categorized under CWE-20 (Improper Input Validation) and has a medium CVSS score of 5.3. No patch or official remediation has been published as of the vulnerability disclosure date.
Potential Impact
The vulnerability allows unauthenticated attackers to use the affected WordPress site as an open mail relay to send arbitrary emails to any recipient. This can lead to abuse such as spam distribution or reputation damage to the hosting domain. There is no direct impact on confidentiality or availability reported. No known exploits in the wild have been documented.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, consider disabling or restricting access to the vulnerable REST API endpoint if possible. Monitor for updates from the plugin vendor and apply any official patches promptly once available.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Wordfence
- Date Reserved
- 2026-04-20T14:13:26.851Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e6e4ee19fe3cd2cd6b0eaf
Added to database: 4/21/2026, 2:46:06 AM
Last enriched: 4/21/2026, 3:01:10 AM
Last updated: 4/21/2026, 5:45:40 AM
Views: 9
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