CVE-2026-65051: Ninja Forms Server-Side Validation Bypass via Client-Controlled Field Metadata Merge in AJAX Submission Handler

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.5%

EPSS score, percentile 42.1 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

6.9 Medium

CVSS v4.0 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

Advisories and patches (1)

Which versions are affected?

Affected

• before 3.14.9

Unaffected 3.14.9

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

• Vendor Changelog (Patch)

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Versions not listed are: affected.

Versions the record lists as unaffected: 3.14.9.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

Ninja Forms WordPress plugin version 3.14.8 contains a client-side enforcement of server-side security vulnerability that allows unauthenticated attackers to bypass all form validation by merging attacker-controlled field metadata over server-loaded form definitions before validation runs. Attackers can craft a malicious AJAX submission overriding field types, removing required flags, and disabli…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-65051 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 21 Jul 2026.
• The CVE record carries a CVSS v4.0 base score of 6.9 (Medium), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.5% (percentile 42.1), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation none, automatable yes, technical impact partial.
• The credits in the CVE record name AISLE as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

Description

Ninja Forms Server-Side Validation Bypass via Client-Controlled Field Metadata Merge in AJAX Submission Handler

Ninja Forms WordPress plugin version 3.14.8 contains a client-side enforcement of server-side security vulnerability that allows unauthenticated attackers to bypass all form validation by merging attacker-controlled field metadata over server-loaded form definitions before validation runs. Attackers can craft a malicious AJAX submission overriding field types, removing required flags, and disabling CAPTCHA checks through the nopriv AJAX endpoint to trigger form actions such as email notifications and database storage with unverified, attacker-controlled content.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline