CVE-2025-13993

MediumCVSS 5.5

Published: 12/12/2025(UTC)Updated: 07/10/2026(UTC)Translated: 08/10/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.34%

26th percentile - higher than 26% of all known CVEs

Summary

The MailerLite – Signup forms (official) plugin for WordPress is vulnerable to stored cross-site scripting via the 'form_description' and 'success_message' parameters in versions up to, and including, 1.7.16 due to insufficient input sanitization and output escaping. An authenticated attacker with administrator access or higher can inject arbitrary web scripts into pages.

Risk Assessment

An attacker with administrator privileges can inject malicious scripts that execute for users visiting the affected pages. This can lead to session theft, redirects, or other browser-based attacks against victims.

Recommendation

Update the MailerLite – Signup forms plugin to a version newer than 1.7.16. Limit the number of administrator accounts and review form content for suspicious scripts.

Other vulnerabilities in MailerLite – Signup forms

CVE-2026-3253Medium
The MailerLite – Signup forms (official) plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the forms() method of the AdminController class in all versions up to, and including, 1.7.21. This makes it possible for authenticated attackers, with Contributor-level access and above, to create or delete arbitrary signup forms.

Original NVD description (English source)

The MailerLite – Signup forms (official) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'form_description' and 'success_message' parameters in versions up to, and including, 1.7.16 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator access or higher, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS