Executive brief
Post SMTP is a popular WordPress plugin used to manage and deliver emails from a website. A security flaw allows an unauthenticated attacker to inject malicious scripts into the site, which could lead to unauthorized actions or data theft when an administrator visits the dashboard. This could result in a full site takeover if a high-privileged user is targeted.
Technical details
A reflected Cross-Site Scripting (XSS) vulnerability exists in the Post SMTP plugin for WordPress due to improper neutralization of input during web page generation (CWE-79). The vulnerability affects versions up to and including 3.6.2. An unauthenticated attacker can exploit this by tricking a privileged user (such as an administrator) into clicking a specially crafted link or visiting a malicious page. Successful exploitation allows the execution of arbitrary JavaScript in the context of the victim's browser session, potentially leading to session hijacking or administrative account takeover. The issue is resolved in version 3.6.3.
Affected products
- WPExperts Post SMTP <= 3.6.2
Timeline
- 2025-11-14: other: Vulnerability reported by researcher mcdruid
- 2026-05-28: patched: Patch released in version 3.6.3
- 2026-06-15: advisory: CVE published to NVD