Drag And Drop Multiple File Upload Contact Form 7 - Remote Code Execution (CVE-2026-5718)
CVE-2026-5718
The Drag and Drop Multiple File Upload for Contact Form 7 plugin for WordPress is vulnerable to arbitrary file upload in versions up to, and including, 1.3.9.7. This is due to insufficient file type validation that occurs when custom blacklist types are configured, which replaces the default dangerous extension denylist instead of merging with it, and the wpcf7_antiscript_file_name() sanitization function being bypassed for filenames containing non-ASCII characters. This makes it possible for unauthenticated attackers to upload arbitrary files, such as PHP files, to the server, which can be leveraged to achieve remote code execution. The vulnerability was originally reported by Leonid Semenenko (lsemenenko) and partially patched in version 1.3.9.7. A bypass for the patch was separately discovered and reported by Nguyen Hung (Mitchell).
CVE-2026-5718
HIGH
CVSS 8.1
Published 2026-04-17
Updated 2026-06-17
AI Risk High (87/100)
Active Exploit: No strong signal
Published Exploit: No public exploit references
Priority: P2 Urgent
Severity Band
HIGH
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Components
2
Reference Links
7
AI Risk Engine
High (87/100)
Exploitability
Very High
Active Exploitation
No strong signal
Published Exploit Status
No public exploit references
AI Context
Machine-generated threat intelligence
AI
Updated 114 days ago
AI enriched 114 days ago (2026-05-28 00:56 UTC)
Technical Summary
The Drag and Drop Multiple File Upload for Contact Form 7 plugin for WordPress is vulnerable to arbitrary file upload in versions up to, and including, 1.3.9.7. This is due to insufficient file type validation that occurs when custom blacklist types are configured, which replaces the default dangerous extension denylist instead of merging with it, and the wpcf7_antiscript_file_name() sanitization function being bypassed for filenames containing non-ASCII characters. This makes it possible for unauthenticated attackers to upload arbitrary files, such as…
Potential Impact
Severity is HIGH (CVSS 8.1). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.
Exploitability Assessment
Exploitability is assessed as Very High based on remote code execution potential, low-bar exploit prerequisites.
Primary risk drivers: remote code execution potential, low-bar exploit prerequisites
Mitigation Recommendations
Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.
Detection & Monitoring
Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.
Business Impact Lens
AI risk score 87/100 (High, Very High) with priority P2 Urgent. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.
