CVE-2026-3551: Custom New User Notification (WordPress plugin) · Cross-site Scripting
Affects Custom New User Notification (WordPress plugin)Source CVE Database V5
Not known to be exploited · CVSS 4.4 Medium.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 16 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| rafasashiCustom New User Notification | Affected
| Fixed in– |
AI-suggested
Until an official fix is released, restrict administrator access to trusted users only and consider disabling or removing the plugin if possible. Monitor for updates from the plugin vendor or WordPress security channels for patches addressing this vulnerability.
Description
The Custom New User Notification plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's admin settings in all versions up to, and including, 1.2.0. This is due to insufficient input sanitization and output escaping on multiple settings fields including 'User Mail Subject', 'User From Name', 'User From Email', 'Admin Mail Subject', 'Admin From Name', and 'Admin From Email'. The settings are registered via register_setting() without sanitize callbacks, and the values retrieved via get_option() are echoed directly into HTML input value attributes without esc_attr(). This makes it possible for authenticated attackers, with Administrator-level access and above, to inject arbitrary web scripts in the plugin settings page that will execute whenever a user accesses that page. This could be used in multi-site installations where administrators of subsites could target super administrators.
References
- wordfence.com/threat-intel/vulnerabilities/id/7a14d35d-144c-4ddd-b288-5e0e006fb165?source=cve (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/trunk/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/tags/1.2.0/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/trunk/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/tags/1.2.0/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/trunk/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/tags/1.2.0/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/trunk/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/tags/1.2.0/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/trunk/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/tags/1.2.0/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/trunk/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/tags/1.2.0/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/trunk/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/tags/1.2.0/admin/includes.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/trunk/custom-new-user-notification.php (opens in a new tab)
- plugins.trac.wordpress.org/browser/custom-new-user-notification/tags/1.2.0/custom-new-user-notification.php (opens in a new tab)