Compliance Impact

The vulnerability in Emlog Pro v2.6.9 allows authenticated administrators to execute arbitrary PHP code via a path traversal attack in the template upload feature. This can lead to full server compromise and persistent unauthorized code execution.

Such a compromise can result in unauthorized access to sensitive data, potential data breaches, and loss of data integrity, which negatively impacts compliance with common standards and regulations like GDPR and HIPAA that require protection of personal and sensitive information.

Organizations using vulnerable versions of Emlog Pro may face increased risk of non-compliance due to the possibility of data exposure or manipulation caused by this vulnerability.

Useful 0 Not Useful 0

Executive Summary

CVE-2026-39276 is a critical path traversal vulnerability in the template upload feature of Emlog Pro version 2.6.9 and earlier. It allows authenticated administrators to upload malicious ZIP archives containing directory traversal sequences in filenames.

When these ZIP files are extracted, the traversal sequences enable overwriting of default template files such as header.php or footer.php. This leads to the execution of arbitrary PHP code on the server.

The root cause is improper sanitization and validation of filenames during extraction in the emUnZip() and extractTo() functions, which fail to prevent directory traversal attacks.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability can have severe impacts including remote code execution on the server hosting Emlog Pro.

• Attackers can gain full control over the server by executing arbitrary PHP code.
• They can persistently compromise the system by modifying default template files that are loaded whenever visitors access the site.
• This can lead to data breaches, defacement, or use of the server for further attacks.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability can be detected by checking for unauthorized or suspicious modifications to template files such as header.php or footer.php in the Emlog Pro installation directory, especially after uploads via the template upload feature.

Since the vulnerability involves uploading malicious ZIP archives containing directory traversal sequences, you can look for ZIP files with filenames containing sequences like "../" or similar patterns.

Suggested commands to detect potential exploitation include:

• Use grep to find suspicious directory traversal patterns in uploaded ZIP files or extracted filenames: `grep -r "\.\./" /path/to/emlog/templates/`
• Check for recent changes to critical template files: `find /path/to/emlog/templates/ -name "header.php" -o -name "footer.php" -exec ls -l --time-style=full-iso {} +`
• Inspect web server logs for POST requests to `/admin/template.php` that include file uploads, which may indicate attempts to exploit the vulnerability.

Useful 0 Not Useful 0

Mitigation Strategies

Immediate mitigation steps include restricting access to the template upload feature to only trusted and authenticated administrators.

Avoid uploading ZIP archives from untrusted sources and verify the contents of any uploaded ZIP files before extraction.

Implement or apply patches that enforce strict path validation and prevent directory traversal sequences in filenames during ZIP extraction.

Monitor and audit template files for unauthorized changes and restore any compromised files from a known good backup.

If possible, temporarily disable the template upload feature until a secure fix or update is applied.

Useful 0 Not Useful 0