A critical vulnerability discovered in mcp-server-git versions prior to 2025.12.17 allows attackers to bypass repository access restrictions through path traversal attacks. This CVE-2025-68145 represents a significant security risk for AI agent deployments using MCP (Model Context Protocol) servers, potentially exposing sensitive repositories and data beyond intended boundaries.
How the Attack Works
The vulnerability stems from improper validation of the repo_path argument when the server is started with the --repository flag. Attackers can exploit this by injecting directory traversal sequences like ../ into the repository path parameter, allowing access to directories outside the intended repository root.
In a typical MCP server deployment, the server should restrict access to a specific repository directory. However, without proper path validation, an attacker could craft a malicious request that navigates up the directory tree and accesses sensitive files or repositories. For example, a payload like --repository "../../../etc/passwd" could potentially expose system files, while --repository "../competitor-repo" might reveal proprietary codebases.
The attack surface expands significantly when considering that MCP servers often operate with elevated privileges to perform git operations. This means successful exploitation could grant attackers access to any directory the server process can read, making this vulnerability particularly dangerous in multi-tenant environments or shared hosting scenarios.
Real-World Implications for AI Agents
AI agents relying on mcp-server-git for repository operations face severe risks from this vulnerability. Many production deployments use MCP servers to provide AI systems with controlled access to code repositories, documentation, and configuration files. A successful path traversal attack could expose API keys, database credentials, proprietary algorithms, or customer data stored in adjacent directories.
Consider an AI development environment where an agent has access to a specific project repository through mcp-server-git. If an attacker exploits this vulnerability, they could potentially access the entire filesystem structure, including configuration files containing service credentials, environment variables, or other sensitive data that the AI system shouldn't have access to.
The implications extend beyond data exposure. Attackers could manipulate repository contents, inject malicious code into CI/CD pipelines, or corrupt version control history. In enterprise environments where AI agents handle multiple customer projects, this vulnerability could enable cross-customer data access, violating compliance requirements and data isolation policies.
Immediate Defensive Measures
Organizations using mcp-server-git must take immediate action to protect their deployments. First, upgrade to version 2025.12.17 or later immediately. This patched version includes proper path validation that prevents directory traversal attempts. Until an upgrade is possible, implement strict access controls and monitoring.
import os
from pathlib import Path
def validate_repo_path(repo_path: str, allowed_base: str) -> bool:
"""
Validate repository path to prevent directory traversal
"""
# Resolve to absolute path
abs_repo = Path(repo_path).resolve()
abs_base = Path(allowed_base).resolve()
# Ensure the repository path is within the allowed base directory
try:
abs_repo.relative_to(abs_base)
return True
except ValueError:
return False
# Example usage in MCP server configuration
allowed_base_path = "/srv/git-repos"
repo_path = request.args.get("repo_path", "")
if not validate_repo_path(repo_path, allowed_base_path):
raise PermissionError("Repository path outside allowed directory")
Additionally, implement chroot environments or container isolation to limit the server's filesystem access. Run the MCP server with minimal privileges, restricting its access to only necessary directories. Enable comprehensive logging to detect potential exploitation attempts, monitoring for suspicious path patterns or access to unusual directories.
Long-Term Security Strategies
Beyond the immediate patch, organizations should adopt defense-in-depth strategies for MCP server deployments. Implement the principle of least privilege by configuring servers with minimal necessary permissions. Use separate, dedicated user accounts with restricted filesystem access for running MCP services.
Consider implementing a whitelist-based approach for repository access. Instead of accepting arbitrary paths, maintain an explicit list of allowed repositories and validate against this list. This approach eliminates the possibility of path traversal attacks by design.
# Example MCP server configuration with repository whitelist
mcp_server:
git:
enabled: true
allowed_repositories:
- "/srv/repos/project-alpha"
- "/srv/repos/project-beta"
- "/srv/repos/shared-docs"
security:
enable_path_validation: true
restrict_symlinks: true
max_path_depth: 3
audit_logging: true
Regular security audits should include MCP server configurations and access patterns. Implement automated scanning for vulnerable versions in your infrastructure, and establish incident response procedures specifically for MCP-related security events. Consider using the .mcpignore mechanism mentioned in the MCPIgnore Filesystem MCP server documentation to prevent access to sensitive files even within allowed repositories.
Conclusion
CVE-2025-68145 serves as a critical reminder that even specialized tools like MCP servers require rigorous security scrutiny. The path traversal vulnerability in mcp-server-git versions before 2025.12.17 poses significant risks to AI agent deployments, potentially exposing sensitive data and compromising entire systems.
Immediate action is required: upgrade to the patched version, implement path validation controls, and audit your current deployments for signs of compromise. For long-term security, adopt defense-in-depth strategies including container isolation, privilege restrictions, and comprehensive monitoring. The original CVE disclosure at https://nvd.nist.gov/vuln/detail/CVE-2025-68145 provides additional technical details and should be referenced for complete vulnerability information.