CVE-2026-3695: Modern Image Gallery App Path Traversal

CVE-2026-3695 Overview

A path traversal vulnerability has been identified in SourceCodester Modern Image Gallery App version 1.0. The vulnerability exists in the /delete.php file, where improper handling of the filename argument allows attackers to manipulate file paths. This weakness enables remote attackers to traverse directory structures and potentially delete arbitrary files on the affected system.

Critical Impact

Remote attackers can exploit this path traversal vulnerability to manipulate file paths via the filename parameter, potentially leading to unauthorized file deletion and system integrity compromise.

Affected Products

• SourceCodester Modern Image Gallery App 1.0
• Remyandrade Modern Image Gallery App (all installations using vulnerable version)

Discovery Timeline

• 2026-03-08 - CVE-2026-3695 published to NVD
• 2026-03-09 - Last updated in NVD database

Technical Details for CVE-2026-3695

Vulnerability Analysis

This vulnerability is classified as CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), commonly known as path traversal or directory traversal. The vulnerable endpoint /delete.php accepts a filename parameter that is not properly sanitized before being used in file system operations.

The application fails to validate or sanitize user-supplied input in the filename parameter, allowing attackers to include directory traversal sequences such as ../ to escape the intended directory and access files elsewhere on the file system. Since this is a delete operation, successful exploitation could result in the removal of critical system files or application data.

The vulnerability is remotely exploitable without requiring authentication, meaning any attacker with network access to the application can attempt to exploit it. The public disclosure of this exploit increases the risk of widespread exploitation attempts.

Root Cause

The root cause of this vulnerability is insufficient input validation in the /delete.php script. The application does not implement proper path canonicalization or restrict the filename parameter to a designated upload directory. Without sanitizing path traversal sequences (such as ../, ..\, or URL-encoded variants), the application blindly processes user-controlled file paths in delete operations.

Attack Vector

The attack is network-based and can be launched remotely against any exposed instance of the Modern Image Gallery App. An attacker crafts a malicious HTTP request to /delete.php with a manipulated filename parameter containing path traversal sequences. For example, by supplying values like ../../../etc/important_file or similar traversal patterns, the attacker can target files outside the intended upload directory.

The vulnerability mechanism allows attackers to:

1. Send HTTP requests to the vulnerable /delete.php endpoint
2. Include path traversal sequences in the filename parameter
3. Target files outside the application's upload directory
4. Delete arbitrary files accessible by the web server process

Technical details and proof-of-concept information are available in the GitHub Gist PoC Details.

Detection Methods for CVE-2026-3695

Indicators of Compromise

• HTTP requests to /delete.php containing path traversal sequences such as ../, ..%2f, ..%5c, or similar encoded variants
• Unusual file deletion activity or missing files outside the application's upload directory
• Web server logs showing repeated requests to /delete.php with suspicious filename parameters
• Error logs indicating failed file operations or permission denied messages for unexpected file paths

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing path traversal patterns in the filename parameter
• Configure intrusion detection systems (IDS) to alert on HTTP requests to /delete.php with suspicious path patterns
• Enable detailed access logging for the web server and monitor for anomalous requests to sensitive endpoints
• Deploy file integrity monitoring to detect unexpected file deletions across the system

Monitoring Recommendations

• Monitor HTTP access logs for requests to /delete.php with encoded or unencoded traversal sequences
• Set up alerts for any file deletion events outside the designated upload directory
• Track web server process file access patterns to identify attempts to access files outside normal application paths
• Review application error logs for path-related exceptions or security warnings

How to Mitigate CVE-2026-3695

Immediate Actions Required

• Restrict network access to the vulnerable application until patched
• Implement web application firewall rules to block path traversal attempts in the filename parameter
• Disable or remove the /delete.php endpoint if file deletion functionality is not critical
• Apply filesystem permissions to limit the web server process's access to only necessary directories

Patch Information

No official vendor patch has been announced at this time. Organizations using the SourceCodester Modern Image Gallery App should monitor the SourceCodester website for security updates. Additional vulnerability details are available through VulDB #349641.

Workarounds

• Implement server-side input validation to reject any filename values containing path traversal sequences (../, ..\, encoded variants)
• Use a whitelist approach that only allows filenames matching expected patterns (alphanumeric characters, allowed extensions)
• Configure the web server to restrict the application's file access to a designated upload directory using open_basedir (PHP) or similar controls
• Deploy the application behind a reverse proxy with request filtering capabilities

# Example: PHP open_basedir restriction in php.ini or .htaccess
# Restricts PHP file operations to the specified directory
open_basedir = /var/www/html/gallery/uploads/

# Example: Apache mod_rewrite rule to block traversal attempts
RewriteEngine On
RewriteCond %{QUERY_STRING} (\.\./|\.\.\\) [NC,OR]
RewriteCond %{QUERY_STRING} (\.\.%2f|\.\.%5c) [NC]
RewriteRule ^delete\.php$ - [F,L]