An authenticated path traversal vulnerability in the Sooperset mcp-atlassian server allows attackers to read sensitive local files, posing a significant risk of unauthorized data exposure.

The application fails to properly sanitize input in the upload_attachment function, permitting the use of absolute paths and traversal sequences. This allows an authenticated caller with attachment access to bypass directory restrictions and access files outside the intended server workspace.

Successful exploitation of this vulnerability can lead to the unauthorized disclosure of sensitive system configuration files, credentials, or proprietary data stored on the host running the MCP server. Given the CVSS score of 6.5, this vulnerability represents a significant risk to data confidentiality, as it facilitates the exfiltration of information that could be leveraged for further attacks against the Atlassian infrastructure.

Immediate Action: Update the mcp-atlassian package to version 0.22.0 or later to implement the necessary path validation controls.

Proactive Monitoring: Review application access logs for unusual file path requests or repeated attempts to access system directories using traversal sequences.

Compensating Controls: Implement strict network segmentation and apply Principle of Least Privilege to limit the access rights of MCP callers, ensuring they can only interact with necessary components.

Public Exploit Available: Unknown

Organizations utilizing the mcp-atlassian server should prioritize upgrading to version 0.22.0 immediately. Because this flaw allows for the unauthorized reading of arbitrary files, it remains a critical concern for environments handling sensitive Jira or Confluence data. Promptly applying the vendor patch is the only effective way to remediate the underlying path traversal flaw.