MCP Atlassian, a server component used with Atlassian Confluence and Jira, contains a path traversal flaw in the upload_attachment endpoint that allows an attacker to supply a file_path that refers to any file on the host file system. By crafting an absolute or relative path with traversal sequences, a malicious caller can cause the server to read and return the contents of that file, resulting in confidential data disclosure. The weakness is a classic file path injection (CWE-22) and demonstrates a lack of proper input validation for file paths used during upload operations.

All installations of SooperSet MCP Atlassian older than version 0.22.0 are vulnerable. The flaw affects the core upload_attachment functionality and its handling of the file_path parameter, regardless of the specific Atlassian product it serves. Any deployment that uses the unpatched MCP Atlassian component is at risk.

The CVSS score of 6.5 indicates a moderate severity vulnerability. No EPSS score is currently reported, so the likelihood of exploitation cannot be quantified from available data. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Based on the description, the attack vector is likely an unauthenticated or authenticated request to the upload_attachment endpoint; however, the precise authentication requirements are not specified in the input and are therefore inferred. Once an attacker can submit a malicious upload request, the flaw can be exploited to read arbitrary files on the server without any additional steps. The issue is rectified in MCP Atlassian version 0.22.0, which limits upload file paths to a safe directory.