What the vulnerability does
01Description
The twinklesmtp – Email Service Provider For WordPress plugin for WordPress is vulnerable to Stored Cross-Site Scripting via plugin's sender settings in all versions up to, and including, 1.03 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.
Explanation of Vulnerability in Simple Terms
02Summary
The Twinkle SMTP plugin for WordPress contains a stored cross-site scripting (XSS) vulnerability in versions 1.03 and earlier. An authenticated administrator with high privileges can inject malicious scripts that affect other users across the site. The vulnerability requires high attack complexity and does not require user interaction to execute, but impact is limited to low-level information disclosure and modification.
What an attacker can do
03Attacker Capabilities
Inject malicious scripts that execute in other users' browsers and modify site content.
Potential impact on your site
04Site Impact
A malicious admin account can inject scripts affecting other users; update the plugin immediately.
Conditions required to exploit
05Prerequisites
Attacker must be an authenticated administrator with high-level WordPress privileges.
Key dates
06Disclosure timeline
January 7, 2026
CVE published
April 8, 2026
Record updated
