CVE-2026-75962
Post SMTP <= 4.0.1 - Unauthenticated Stored DOM-Based Cross-Site Scripting via 'user_email' Parameter (Multisite Registration → Failed Email Log)
- State
- Published
- Severity
- 7.2 High
- Published
- Oct 6, 2026
- Updated
- Oct 9, 2026
- Reserved
- Aug 18, 2026
Description
The Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'user_email' parameter in all versions up to, and including, 4.0.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This is exploitable without authentication on WordPress Multisite installations with public registration enabled, as WordPress accepts email addresses containing numeric HTML character references that Post SMTP's stricter validator rejects, persisting the attacker-controlled address verbatim to the email log via the failed-send exception message.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.2 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N | Wordfence |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
Post SMTP – Complete Email Delivery and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile Appsaadiqbal |
|
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/accac3da-0318-4e79-a163-ed9ff2af692b?source=cve
- https://plugins.trac.wordpress.org/browser/post-smtp/tags/3.9.5/Postman/PostmanWpMail.php#L374
- https://plugins.trac.wordpress.org/browser/post-smtp/tags/3.9.5/script/postman-email-logs.js#L711
- https://plugins.trac.wordpress.org/browser/post-smtp/tags/3.9.5/Postman/PostmanEmailLogs.php#L538
- https://plugins.trac.wordpress.org/browser/post-smtp/tags/3.9.5/Postman/Postman-Email-Log/PostmanEmailLogService.php#L215
- https://plugins.trac.wordpress.org/browser/post-smtp/tags/3.9.5/Postman/Postman-Mail/PostmanEmailAddress.php#L63
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3711079%40post-smtp%2Ftags%2F4.0.2&old=3664536%40post-smtp%2Ftags%2F4.0.1
- https://plugins.trac.wordpress.org/changeset/3711068/post-smtp/trunk/Postman/Postman-Email-Log/PostmanEmailLogService.php
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