What the vulnerability does
01Description
The Popup Builder by OptinMonster – WordPress Popups for Optins, Email Newsletters and Lead Generation plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘campaign_id’ parameter in versions up to, and including, 2.16.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Explanation of Vulnerability in Simple Terms
02Summary
OptinMonster versions up to 2.16.1 contain a stored cross-site scripting (XSS) vulnerability. An authenticated user with low privileges can inject malicious scripts into popup content that execute in the browsers of other site visitors and administrators. The vulnerability affects the scope beyond the plugin itself, potentially compromising site security and user data.
What an attacker can do
03Attacker Capabilities
Inject malicious JavaScript that runs in visitors' browsers when they view affected popups.
Potential impact on your site
04Site Impact
Visitors and admins may have their sessions hijacked, credentials stolen, or malware injected via popup content.
Conditions required to exploit
05Prerequisites
Attacker must have a low-privilege WordPress account (e.g., subscriber or contributor role).
Key dates
06Disclosure timeline
May 25, 2024
CVE published
April 8, 2026
Record updated
