CVE-2021-34648

Name: CVE-2021-34648
Creator: NVD / NIST
Published: 2021-09-22T18:15:11.99+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.64%

Last modified Jun 17, 2026

CVE-2021-34648 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. The Ninja Forms WordPress plugin is vulnerable to arbitrary email sending via the trigger_email_action function found in the ~/includes/Routes/Submissions.php file, in versions up to and including 3.5.7. This allows authenticated attackers to send arbitrary emails from the affected server via the /ninja-forms-submissions/email-action REST API which can be used to socially engineer victims.. EPSS estimates a 0.64% chance of exploitation in the next 30 days.

Description

The Ninja Forms WordPress plugin is vulnerable to arbitrary email sending via the trigger_email_action function found in the ~/includes/Routes/Submissions.php file, in versions up to and including 3.5.7. This allows authenticated attackers to send arbitrary emails from the affected server via the /ninja-forms-submissions/email-action REST API which can be used to socially engineer victims.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS Probability

0.64%

45.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Ninjaforms	Ninja Forms	<= 3.5.7

References

https://plugins.trac.wordpress.org/browser/ninja-forms/trunk/includes/Routes/Submissions.php?rev=2543837#L155Patch, Third Party Advisory
https://www.wordfence.com/blog/2021/09/recently-patched-vulnerabilities-in-ninja-forms-plugin-affects-over-1-million-site-owners/Exploit, Third Party Advisory
https://plugins.trac.wordpress.org/browser/ninja-forms/trunk/includes/Routes/Submissions.php?rev=2543837#L155Patch, Third Party Advisory
https://www.wordfence.com/blog/2021/09/recently-patched-vulnerabilities-in-ninja-forms-plugin-affects-over-1-million-site-owners/Exploit, Third Party Advisory

Timeline

Published: Sep 22, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34648?

How severe is CVE-2021-34648?

CVE-2021-34648 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.64% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34648?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-34648?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST