CVE-2026-2863: SSM-ERP Path Traversal Vulnerability

CVE-2026-2863 Overview

A path traversal vulnerability has been identified in feng_ha_ha/megagao ssm-erp and production_ssm (up to commit 4288d53bd35757b27f2d070057aefb2c07bdd097). The vulnerability exists in the deleteFile function within the FileServiceImpl.java file, allowing attackers to manipulate file paths and potentially delete arbitrary files on the system. This flaw can be exploited remotely by authenticated users, posing a risk to data integrity and system availability.

Critical Impact

Remote attackers with low-level privileges can exploit improper path validation in the file deletion functionality to traverse directories and delete arbitrary files, potentially causing data loss or service disruption.

Affected Products

• feng_ha_ha/megagao ssm-erp (up to commit 4288d53bd35757b27f2d070057aefb2c07bdd097)
• feng_ha_ha/megagao production_ssm (up to commit 4288d53bd35757b27f2d070057aefb2c07bdd097)
• Rolling release versions prior to vulnerability disclosure

Discovery Timeline

• 2026-02-21 - CVE-2026-2863 published to NVD
• 2026-02-23 - Last updated in NVD database

Technical Details for CVE-2026-2863

Vulnerability Analysis

This path traversal vulnerability (CWE-22) occurs in the file deletion functionality of the ssm-erp and production_ssm applications. The deleteFile function in FileServiceImpl.java fails to properly sanitize user-supplied file path input before performing file operations. Attackers can inject directory traversal sequences (such as ../) to escape the intended directory and target files in arbitrary locations on the filesystem.

The vulnerability requires network access and low-level authentication to exploit. While the attack complexity is low and requires no user interaction, the impact is limited to integrity and availability effects rather than confidentiality breaches. An exploit has been publicly disclosed, increasing the risk of active exploitation.

Root Cause

The root cause of this vulnerability is insufficient input validation in the deleteFile function. The application does not properly validate or sanitize file path parameters before using them in file system operations. Specifically, the code fails to:

• Canonicalize file paths to resolve symbolic links and relative references
• Validate that the resolved path remains within the intended directory boundary
• Strip or reject path traversal sequences like ../ or ..\\

This allows attackers to craft malicious file path inputs that escape the designated upload or file storage directory.

Attack Vector

The attack is initiated remotely over the network. An authenticated attacker with low privileges can send specially crafted requests to the file deletion endpoint. By including path traversal sequences in the filename parameter, the attacker can direct the deleteFile function to target files outside the intended directory structure.

For example, an attacker could supply a filename such as ../../../etc/important_config to traverse up the directory tree and target critical system or application files. Since the vulnerability affects file deletion operations, successful exploitation results in unauthorized removal of files, potentially causing data loss, service disruption, or denial of service conditions.

Technical details and the original vulnerability report can be found in the GitHub Issue #37 on the production_ssm repository.

Detection Methods for CVE-2026-2863

Indicators of Compromise

• File deletion requests containing path traversal sequences such as ../, ..\\, or encoded variants (%2e%2e%2f)
• Unusual file deletion activity targeting files outside expected upload directories
• Web server logs showing requests to file-related endpoints with suspicious path patterns
• Missing or unexpectedly deleted system or configuration files

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing directory traversal patterns
• Monitor application logs for file operation requests with path traversal sequences
• Deploy file integrity monitoring (FIM) to detect unauthorized file deletions across critical directories
• Configure intrusion detection systems (IDS) with signatures for path traversal attack patterns

Monitoring Recommendations

• Enable detailed logging for all file system operations in the application
• Set up alerts for file deletion requests targeting paths outside designated directories
• Monitor for repeated failed file operation attempts which may indicate exploitation attempts
• Review access logs for the FileServiceImpl endpoints regularly for anomalous patterns

How to Mitigate CVE-2026-2863

Immediate Actions Required

• Restrict access to file management functionality to only trusted, authenticated users
• Implement input validation to reject file paths containing traversal sequences
• Deploy a web application firewall with rules to block path traversal attacks
• Audit recent file deletion activity to identify potential compromise

Patch Information

No official patch information is currently available. The project uses continuous delivery with rolling releases, making specific version tracking difficult. The vendor was informed of the vulnerability through GitHub Issue #37 but has not yet responded. Organizations should monitor the repository for updates and consider implementing custom fixes or workarounds until an official patch is released.

Additional vulnerability details are available through VulDB #347102.

Workarounds

• Implement server-side path canonicalization and validate that resolved paths remain within allowed directories
• Add input sanitization to strip or reject path traversal sequences before processing file operations
• Use allowlists for permitted file names and directories rather than relying on blocklists
• Consider temporarily disabling the file deletion functionality if not business-critical until a patch is available

# Example mitigation: Restrict file operations to specific directory
# Add to your application configuration or implement in code
# Ensure all file paths are canonicalized and validated

# For Java applications, implement path validation:
# 1. Get canonical path of the target file
# 2. Get canonical path of the allowed base directory  
# 3. Verify the target path starts with the base directory path
# 4. Reject the operation if validation fails