CVE-2026-6675 json
Responsive Blocks <= 2.2.0 - Unauthenticated Open Email Relay via REST API 'email_to' Parameter
published 2026-04-21 6 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-24058
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 25%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.33% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |
Affected products
- cyberchimps Responsive Blocks – Page Builder for Blocks & Patterns
Classification
- Weakness
-
- CWE-20 Improper Input Validation
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/17452a29-bcef-451a-9893-a436ac5d3b80?source=cve
- plugins.trac.wordpress.org /browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2403
- 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 /browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2212
- 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 /browser/responsive-block-editor-addons/trunk/includes/class-responsive-block-editor-addons.php#L2324
- plugins.trac.wordpress.org /browser/responsive-block-editor-addons/tags/2.1.9/includes/class-responsive-block-editor-addons.php#L2324
Sources
- CVE List CVE-2026-6675
- NVD CVE-2026-6675
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.