What is CVE-2026-3253?

CVE-2026-3253 is a medium-severity vulnerability in Mailerlite – Signup Forms (Official), classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-09-24.

How severe is CVE-2026-3253?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Auth bypass in Mailerlite – Signup Forms (Official)

CVE-2026-3253

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.

Vulnerability class: Broken Access Control

Published 2026-09-24 · last modified 2026-09-24.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Mailerlite – Signup Forms (Official)

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

Frequently asked questions

What is CVE-2026-3253?: CVE-2026-3253 is a medium-severity vulnerability in Mailerlite – Signup Forms (Official), classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-09-24.
How severe is CVE-2026-3253?: Medium severity. CVSS v3 base score is 4.3 out of 10.