Critical Vulnerability in Ninja Forms Plugin Exposes 50,000 WordPress Sites to RCE
Severity: High (Score: 78.0)
Sources: Infosecurity-Magazine, Bleepingcomputer, Cybersecuritynews, Scworld, Gbhackers
Published: · Updated:
Keywords: wordpress, ninja, forms, file, upload, critical, flaw
Severity indicators: critical, vulnerability, flaw, rce
Summary
A critical vulnerability (CVE-2026-0740) in the Ninja Forms File Uploads plugin for WordPress allows unauthenticated attackers to upload arbitrary files, potentially leading to remote code execution. This flaw, with a CVSS score of 9.8, affects versions up to 3.3.26 and has been actively exploited, with over 3,600 attacks blocked in the last 24 hours by Wordfence. Approximately 50,000 websites utilizing this plugin are at risk, as the vulnerability stems from inadequate validation of file types during upload. Discovered by researcher Sélim Lanouar, the flaw was reported on January 8, 2026, and a complete fix was released on March 19, 2026. Users are strongly advised to upgrade to the latest version to mitigate risks. The potential impact includes complete site takeover and deployment of web shells. Key Points: • CVE-2026-0740 allows arbitrary file uploads without authentication. • Over 50,000 WordPress sites using Ninja Forms are vulnerable to exploitation. • A complete fix was released on March 19, 2026; users must upgrade immediately.
Detailed Analysis
**Impact** Approximately 50,000 WordPress websites using the Ninja Forms File Upload premium add-on are vulnerable to remote code execution (RCE). The plugin has over 600,000 downloads, with 90,000 customers for the File Upload extension, indicating broad exposure across multiple sectors relying on WordPress for web presence. Exploitation can lead to complete site takeover, including deployment of web shells, potentially compromising business operations and sensitive data hosted on affected sites. **Technical Details** The vulnerability, tracked as CVE-2026-0740 with a CVSS score of 9.8, allows unauthenticated attackers to upload arbitrary files, including PHP scripts, due to lack of file type validation and filename sanitization. Attackers exploit path traversal to place malicious files in the webroot, enabling remote code execution. The flaw affects Ninja Forms File Upload versions up to 3.3.26. Wordfence has observed thousands of exploitation attempts daily and deployed firewall rules as temporary mitigations. No specific malware or IOCs were detailed in the sources. **Recommended Response** Administrators should immediately upgrade Ninja Forms File Upload to version 3.3.27 or later, which contains the complete fix. Deploy firewall rules or web application firewall (WAF) signatures to block exploitation attempts if patching is delayed. Monitor web server logs for suspicious file uploads and access to PHP files in upload directories. Maintain vigilance for indicators of compromise related to web shells or unauthorized file execution.
Source articles (6)
- 50,000 WordPress Sites Running Ninja Forms Vulnerable to Critical File Upload RCE — Gbhackers · 2026-04-07
A severe security flaw has been discovered in the Ninja Forms File Upload plugin, a widely utilized WordPress add-on that allows website administrators to accept documents, images, and other media fro… - 50,000 WordPress Sites Exposed to Critical Ninja Forms File Upload RCE Vulnerability — Cybersecuritynews · 2026-04-07
A critical security flaw in the popular WordPress plugin “Ninja Forms – File Upload” has left approximately 50,000 websites vulnerable to complete takeover. Tracked as CVE-2026-0740, this flaw boasts… - Hackers exploit critical flaw in Ninja Forms WordPress plugin — Bleepingcomputer · 2026-04-07
A critical vulnerability in the Ninja Forms File Uploads premium add-on for WordPress allows uploading arbitrary files without authentication, which can lead to remote code execution. Identified as CV… - Hackers exploit critical flaw in Ninja Forms WordPress plugin — Bleepingcomputer · 2026-04-07
A critical vulnerability in the Ninja Forms File Uploads premium add-on for WordPress allows uploading arbitrary files without authentication, which can lead to remote code execution. Identified as CV… - Critical Vulnerability in Ninja Forms Exposes WordPress Sites — Infosecurity-Magazine · 2026-04-08
A critical arbitrary file upload vulnerability in Ninja Forms – File Upload Plugin has been identified, exposing thousands of WordPress sites to potential compromise. The issue affects plugin versions… - Critical Ninja Forms vulnerability allows remote code execution | brief — Scworld · 2026-04-08
A critical vulnerability in the Ninja Forms File Uploads premium add-on for WordPress enables unauthenticated arbitrary file uploads, potentially leading to remote code execution. This flaw, identifie…
Timeline
- 2026-01-08 — Vulnerability discovered and reported to Wordfence
- 2026-02-10 — Partial fix released after patch reviews
- 2026-03-19 — Complete fix released in version 3.3.27
- 2026-04-07 — CVE-2026-0740 published, active exploitation reported
CVEs
Related entities
- Malware (Attack Type)
- Zero-day Exploit (Attack Type)
- T1505.003 - Web Shell (Mitre Attack)
- Ninja Forms (Platform)
- WordPress (Platform)