CVE-2026-1111: PublicCMS Path Traversal Vulnerability

CVE-2026-1111 Overview

A path traversal vulnerability has been discovered in Sanluan PublicCMS versions up to 5.202506.d. This security flaw affects the Save function within the file com/publiccms/controller/admin/sys/TaskTemplateAdminController.java, which is part of the Task Template Management Handler component. By manipulating the path argument, an attacker can exploit this vulnerability to traverse directories and potentially access or modify files outside the intended directory structure. The attack can be executed remotely, and exploit details have been publicly disclosed.

Critical Impact

Remote attackers with high privileges can exploit this path traversal vulnerability to access, read, or potentially overwrite files outside the intended directory, compromising the confidentiality and integrity of the affected system.

Affected Products

• Sanluan PublicCMS up to version 5.202506.d
• Task Template Management Handler component
• TaskTemplateAdminController.java Save function

Discovery Timeline

• 2026-01-18 - CVE-2026-1111 published to NVD
• 2026-01-21 - Last updated in NVD database

Technical Details for CVE-2026-1111

Vulnerability Analysis

This vulnerability is classified as CWE-22 (Path Traversal), a common weakness that allows attackers to access files and directories stored outside the intended directory. In PublicCMS, the Task Template Management Handler fails to properly sanitize the path parameter in the Save function, allowing malicious input containing directory traversal sequences to escape the application's designated file system boundaries.

The vulnerability requires network access and high privileges to exploit, which somewhat limits the attack surface. However, once an authenticated administrative user is compromised or a malicious insider gains access, they can leverage this flaw to read sensitive configuration files, access application source code, or potentially overwrite critical system files depending on the application's file system permissions.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and sanitization of the path argument within the TaskTemplateAdminController.java file. The Save function accepts user-controlled input for file path operations without properly checking for or removing directory traversal sequences such as ../ or encoded variants. This allows attackers to construct malicious paths that navigate outside the intended task template directory.

Attack Vector

The attack is network-based and targets the Task Template Management functionality of PublicCMS. An attacker with administrative privileges can craft a malicious request to the Save function, including directory traversal sequences in the path parameter. This enables access to files and directories that should be restricted, potentially exposing sensitive system information or allowing unauthorized modifications.

The vulnerability allows attackers to manipulate file path parameters by including traversal sequences like ../ to escape the designated directory. When the Save function processes a malicious path without proper sanitization, it can write to or read from arbitrary locations on the file system. For detailed technical information, refer to the GitHub Issue Report and VulDB entry #341703.

Detection Methods for CVE-2026-1111

Indicators of Compromise

• Unusual file access patterns in web server logs showing directory traversal sequences (../, ..%2f, %2e%2e/)
• Unexpected file modifications or access outside the PublicCMS task template directory
• Administrative API requests containing encoded path traversal characters targeting TaskTemplateAdminController
• Log entries showing file operations on sensitive system files from the PublicCMS application context

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing path traversal patterns
• Monitor application logs for requests to the Task Template Management endpoint with suspicious path parameters
• Deploy file integrity monitoring on critical system directories to detect unauthorized access or modifications
• Use SentinelOne's behavioral AI to detect anomalous file system access patterns from web applications

Monitoring Recommendations

• Enable detailed logging for the Task Template Management component in PublicCMS
• Configure alerts for any file operations outside the designated template directories
• Implement real-time monitoring of administrative API endpoints for suspicious activity
• Review access logs regularly for authentication events followed by unusual file path requests

How to Mitigate CVE-2026-1111

Immediate Actions Required

• Restrict access to the Task Template Management functionality to trusted administrators only
• Implement additional access controls and network segmentation for PublicCMS administrative interfaces
• Review and audit existing task templates for any signs of compromise or unauthorized modifications
• Consider temporarily disabling the Task Template Management feature if not critical to operations

Patch Information

At the time of disclosure, the vendor (Sanluan) was contacted but did not respond. No official patch is currently available. Organizations using affected versions of PublicCMS should monitor the official project repository and the VulDB entry for updates regarding security patches. Given the lack of vendor response, consider implementing the workarounds below and evaluating alternative CMS solutions.

Workarounds

• Implement input validation at the web server or reverse proxy level to filter path traversal sequences
• Use a Web Application Firewall (WAF) to block requests containing directory traversal patterns
• Restrict file system permissions for the PublicCMS application user to minimize the impact of successful exploitation
• Apply network-level access controls to limit who can reach administrative interfaces

# Example WAF rule for Apache ModSecurity to block path traversal attempts
SecRule REQUEST_URI "@contains ../" "id:1001,phase:1,deny,status:403,msg:'Path Traversal Attempt Detected'"
SecRule ARGS "@rx \.\.(/|%2f|%252f)" "id:1002,phase:2,deny,status:403,msg:'Path Traversal in Parameters'"