The MCP Atlassian server allows an attacker to cause the server to follow HTTP redirects that lead to internal addresses when using basic‑auth or OAuth authentication branches. Because the redirect‑sanitization hook is omitted, the server will operate on the redirected location without re‑validating it, enabling an attacker to probe internal services, exfiltrate data, or conduct further attacks. This flaw is a typical SSRF vulnerability as defined by CWE‑918.

The product affected is the MCP Atlassian server, released by Sooperset, prior to version 0.22.0. Channels using basic authentication or OAuth personal access tokens are vulnerable. No other versions or branches are listed as impacted.

The scoring system assigns a CVSS base of 7.1, indicating a moderate to high severity. The EPSS value is not provided, and the vulnerability is not listed in the CISA KEV catalog, suggesting no known active exploitation. However, the nature of SSRF means an attacker who can influence the redirect source could force the server to reach internal network addresses, potentially revealing sensitive data or enabling lateral movement. Exploitation would require that the attacker can configure or compromise the connected Atlassian instance so that it returns a redirect header pointing to an internal endpoint. No known public exploitation reports are attached.