WordPress security changelog
MEDIUM CVE-2025-13993 Deferred

MailerLite – Signup forms (official): Cross-site scripting

MailerLite – Signup forms (official) is affected by cross-site scripting. Exploitation requires an authenticated WordPress account. Injected script can execute in the affected site's origin when the vulnerable output is viewed.

CVE / CNA score 5.5 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
MailerLite – Signup forms (official)
Plugin slug
official-mailerlite-sign-up-forms
Affected
See vendor advisory
Safe version
See mitigation notes
Published
Dec 12, 2025
Weakness
CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published Dec 12, 2025 and is one of 5 known issues for this plugin.

What to do

Update, patch or deactivate.

Update MailerLite – Signup forms (official) to a release outside the affected range, or disable and remove it until a fixed version is available.

No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

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.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N

References

Primary and upstream sources