The MCP Atlassian server’s upload_attachment endpoint accepts a caller‑controlled file_path and opens the requested file on the server’s filesystem without enforcing a safe‑path check. This flaw allows an authorized Confluence or Jira MCP caller to read any file that the server process can access and return its contents as an attachment, effectively exposing arbitrary data that may include configuration files, credentials, or other sensitive information. The weakness is a classic path traversal situation, classified as CWE‑22.

All installations of SooperSet MCP Atlassian running a version earlier than 0.22.0 are affected. These deployments expose the upload_attachment logic to Confluence and Jira clients and expose the server to arbitrary file read and exfiltration via the missing validate_safe_path() guard.

The vulnerability carries a CVSS score of 7.7, indicating moderate‑to‑high severity. The EPSS score is not available, and the issue is not listed in CISA’s KEV catalog, so the frequency of exploitation is not quantified. The attack requires the attacker to possess sufficient privileges to invoke the Confluence MCP interface; thus it is limited to users with authorized MCP access. Once authenticated, the attacker can read any server‑accessible file and exfiltrate its contents, presenting a serious confidentiality risk.