# Blockons <= 1.2.19 - Unauthenticated Arbitrary Email Sending via Contact Form Submission REST Endpoint

- **ID:** WPSEC-2026-1058
- **Plugin:** Blockons – Gutenberg blocks for WordPress and WooCommerce websites (`blockons`), https://wordpress.org/plugins/blockons/
- **Affected versions:** from 1.2.04 before 1.2.20
- **Fixed in:** 1.2.20 (Update to 1.2.20 or later.)
- **Severity:** Medium 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
- **Weakness:** CWE-345
- **Usage among sites WPSec scans:** plugin Low, affected versions None seen (as of 2026-10-16)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/blockons
- **Fix released:** 2026-10-15
- **Published:** 2026-10-16
- **URL:** https://wpsec.com/vuln/WPSEC-2026-1058/

## Description

The Blockons plugin for WordPress is vulnerable to arbitrary email sending via the blcns/v1/submit-form REST endpoint in all versions up to, and including, 1.2.19, due to the publicly accessible endpoint taking the recipient, CC, BCC and subject of the notification email from the request instead of from the contact form block's saved settings. This makes it possible for unauthenticated attackers to make the site send emails with attacker-chosen content to arbitrary recipients from the site's own sender address, which can be used for spam or phishing.

## References

- https://wpsec.com/vuln/WPSEC-2026-1058/
- https://plugins.svn.wordpress.org/blockons/tags/1.2.20/
- https://wordpress.org/plugins/blockons/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-1058/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.