Ninja Forms <= 3.15.3 - Unauthenticated PHP Object Injection
| CVE | CVE-2026-91827 |
|---|---|
| CVSS | 8.1 (High) |
| Publicly Published | September 22, 2026 |
| Last Updated | September 29, 2026 |
| Researcher |
Karthik Ramakrishnan
|
Description
The Ninja Forms plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.15.3. This is due to deserialization of untrusted input. This makes it possible for unauthenticated attackers to inject a PHP Object. No known POP chain is present in the vulnerable software. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.
References
Share
Vulnerability Details for Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder
| Software Type | Plugin |
|---|---|
| Software Slug | ninja-forms (view on wordpress.org) |
| Patched? | Yes |
| Remediation | Update to version 3.15.4, or a newer patched version |
| Affected Version |
|
| Patched Version |
|
Recent vulnerabilities in Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder
This record contains material that is subject to copyright.
Copyright 2012-2026 Defiant Inc.
License: Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy. Read more.
Copyright 1999-2026 The MITRE Corporation
License: CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy. Read more.
Have information to add, or spot any errors? Contact us at wfi-support@wordfence.com so we can make any appropriate adjustments.
Did you know Wordfence Intelligence provides free personal and commercial API access to our comprehensive WordPress vulnerability database, along with a free webhook integration to stay on top of the latest vulnerabilities added and updated in the database? Get started today!
Learn moreWant to get notified of the latest vulnerabilities that may affect your WordPress site?
Install Wordfence on your site today to get notified immediately if your site is affected by a vulnerability that has been added to our database.
The Wordfence Intelligence WordPress vulnerability database is completely free to access and query via API. Please review the documentation on how to access and consume the vulnerability data via API.
Documentation