CVE-2021-24134: Constantcontact Constant Contact Forms

Medium severity, CVSS 4.8. EPSS: 0.7% chance of exploitation in the next 30 days.

Unvalidated input and lack of output encoding in the Constant Contact Forms WordPress plugin, versions before 1.8.8, lead to multiple Stored Cross-Site Scripting vulnerabilities, which allowed high-privileged user (Editor+) to inject arbitrary JavaScript code or HTML in posts where the malicious form is embed.

Affected products

• Constantcontact Constant Contact Forms: before 1.8.8 (fixed in 1.8.8)

Published 2021-03-18. Last modified 2026-06-17.