CVE-2024-4045: Optinmonster

Medium severity, CVSS 5.4. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• Optinmonster Optinmonster: before 2.16.2 (fixed in 2.16.2)

Published 2024-05-25. Last modified 2026-06-17.