CVE-2026-6675 Responsive Blocks <= 2.2.0 - Unauthenticated Open Email Relay via REST API 'email_to' Parameter
Unauthenticated attackers can send arbitrary emails via the REST API, turning the site into an open mail relay.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-6675?
CVE-2026-6675 is a medium-severity vulnerability in cyberchimps Responsive Blocks – Page Builder for Blocks & Patterns, published on 21 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-20
Which versions are affected by CVE-2026-6675?
How do I fix CVE-2026-6675?
No fix has been published for CVE-2026-6675 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-6675 being exploited?
There is no known exploitation of CVE-2026-6675 in the wild and no public exploit code.
Sources
Also known as GHSA-jqqm-hx2h-83c5.