CVE-2026-78374 Joomla Extension - joomlart.com - Open mail relay via contact AJAX endpoint in T4 Page Builder extension < 2.3.0
Unauthenticated attackers can use the contact endpoint to send arbitrary emails, 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-2026-78374?
CVE-2026-78374 is a medium-severity vulnerability in joomlart.com T4 Page Builder extension for Joomla, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Joomla Extension - joomlart.com - Open mail relay via contact AJAX endpoint in T4 Page Builder extension < 2.3.0 - The front-end JSON editor endpoint exposes an action called contact that requires no authentication, no CSRF token, no captcha (when no captcha plugin is enabled) and has no rate limiting. The attacker fully controls the recipient, subject and HTML body, and the mail is sent from the site's configured sender identity (mailfrom/fromname).
Weakness: CWE-201
Which versions are affected by CVE-2026-78374?
How do I fix CVE-2026-78374?
No fix has been published for CVE-2026-78374 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-78374 being exploited?
There is no known exploitation of CVE-2026-78374 in the wild and no public exploit code.
Sources
Also known as GHSA-3ghv-6pr7-rjxg.