CVE-2026-1056: Snow Monkey Forms Plugin RCE Vulnerability

CVE-2026-1056 Overview

The Snow Monkey Forms plugin for WordPress contains a critical arbitrary file deletion vulnerability due to insufficient file path validation in the generate_user_dirpath function. This security flaw affects all versions up to and including 12.0.3, enabling unauthenticated attackers to delete arbitrary files on the server without authentication.

Critical Impact

Unauthenticated attackers can delete critical WordPress files such as wp-config.php, potentially leading to remote code execution and complete site takeover.

Affected Products

• Snow Monkey Forms plugin for WordPress versions up to and including 12.0.3
• WordPress installations running vulnerable Snow Monkey Forms versions

Discovery Timeline

• 2026-01-28 - CVE CVE-2026-1056 published to NVD
• 2026-01-29 - Last updated in NVD database

Technical Details for CVE-2026-1056

Vulnerability Analysis

This vulnerability is classified as CWE-22 (Path Traversal), a critical flaw that allows attackers to access or manipulate files outside the intended directory structure. The vulnerability exists in the generate_user_dirpath function within the Snow Monkey Forms plugin, where user-supplied input is not properly validated before being used in file system operations.

The attack can be executed remotely over the network without requiring any authentication or user interaction. The exploitation has low complexity, meaning attackers can reliably exploit this vulnerability with minimal effort. Successful exploitation results in high impact to confidentiality, integrity, and availability—attackers can read sensitive configuration data, modify system files, and cause denial of service by deleting critical files.

Root Cause

The root cause of this vulnerability lies in the insufficient file path validation within the generate_user_dirpath function located in App/Model/Directory.php. The function fails to properly sanitize user-controlled input, allowing path traversal sequences (such as ../) to be processed. This permits attackers to escape the intended directory boundaries and target files anywhere on the file system that the web server process has permissions to delete.

The vulnerable code paths can be traced through multiple files including App/Rest/Route/View.php and the main plugin file snow-monkey-forms.php, where the unsanitized input flows from REST API endpoints to the file deletion operations.

Attack Vector

The attack is conducted over the network through the WordPress REST API endpoints exposed by the Snow Monkey Forms plugin. An unauthenticated attacker can craft malicious requests containing path traversal sequences to target specific files for deletion.

The most dangerous attack scenario involves deleting the wp-config.php file, which contains database credentials and WordPress security keys. When this file is deleted, WordPress enters installation mode, allowing an attacker to reconfigure the site with their own database and gain administrative access, effectively achieving remote code execution.

The vulnerability is particularly severe because it can be accessed through the REST API without any authentication, allowing automated mass exploitation across WordPress installations using vulnerable versions of the Snow Monkey Forms plugin. Technical details of the vulnerable code can be found in the WordPress Plugin Code View and the related View.php endpoint.

Detection Methods for CVE-2026-1056

Indicators of Compromise

• Unexpected HTTP requests to Snow Monkey Forms REST API endpoints containing path traversal patterns (../, ..%2f, ..%5c)
• Missing critical WordPress files such as wp-config.php, .htaccess, or other configuration files
• WordPress site displaying installation wizard unexpectedly
• Web server error logs showing file deletion attempts or permission denied errors for files outside the plugin directory

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block path traversal sequences in requests to /wp-json/snow-monkey-forms/ endpoints
• Monitor WordPress file integrity using security plugins or external monitoring tools to detect unauthorized file deletions
• Enable detailed access logging and analyze logs for suspicious patterns targeting the Snow Monkey Forms plugin REST API
• Deploy SentinelOne Singularity XDR to detect anomalous file system operations initiated by web server processes

Monitoring Recommendations

• Configure alerts for file deletion events in WordPress core directories, especially for wp-config.php and wp-includes/ files
• Implement real-time monitoring of REST API requests for path traversal attack patterns
• Set up automated WordPress health checks to detect when critical files are missing
• Monitor for unusual error patterns in PHP and web server logs that may indicate exploitation attempts

How to Mitigate CVE-2026-1056

Immediate Actions Required

• Update Snow Monkey Forms plugin to the latest patched version immediately
• If immediate update is not possible, deactivate the Snow Monkey Forms plugin until it can be updated
• Review WordPress file integrity to ensure no files have been maliciously deleted
• Check web server access logs for evidence of exploitation attempts

Patch Information

A security patch addressing this vulnerability is available through the WordPress plugin repository. The fix can be reviewed in the WordPress Changeset History. Organizations should update to the latest version of Snow Monkey Forms beyond 12.0.3. For detailed vulnerability information, refer to the Wordfence Vulnerability Report.

Workarounds

• Temporarily disable or deactivate the Snow Monkey Forms plugin if immediate patching is not feasible
• Implement server-level restrictions to block access to the Snow Monkey Forms REST API endpoints from untrusted sources
• Configure web server rules to reject requests containing path traversal sequences targeting the plugin
• Enable additional file system permissions hardening to prevent the web server process from deleting files outside the WordPress uploads directory

# Example: Block path traversal in Apache .htaccess
# Add to WordPress root .htaccess file
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{QUERY_STRING} (\.\./|\.\.%2f|\.\.%5c) [NC,OR]
    RewriteCond %{REQUEST_URI} (\.\./|\.\.%2f|\.\.%5c) [NC]
    RewriteRule .* - [F,L]
</IfModule>