What’s Vulnerable › Vulnerabilities

CVE-2021-24134: Constant Contact Forms < 1.8.8 - Multiple Authenticated Stored XSS

• Severity: medium (CVSS 4.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-03-18 · updated 2026-06-17
• Weakness: CWE-79

Description

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

• Constant Contact Forms: before 1.8.8 — fixed in 1.8.8

How to fix

Upgrade to a fixed version: Constant Contact Forms 1.8.8. Check the vendor advisory for mitigations.

References

• https://wpscan.com/vulnerability/8f3cca92-d072-4806-9142-7f1a987f840b
• https://wpscan.com/vulnerability/8f3cca92-d072-4806-9142-7f1a987f840b

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