GHSA-7r34-79r5-rcc9: MCP Atlassian has SSRF via unvalidated X-Atlassian-Jira-Url / X-Atlassian-Confluence-Url headers

Summary

mcp-atlassian's HTTP middleware and dependency layer accept an unvalidated X-Atlassian-Jira-Url (and the Confluence equivalent) from unauthenticated requests when no Authorization header is present. The server then issues an outbound GET to {header_url}/rest/api/2/myself, enabling server-side request forgery, which the advisory says can expose IAM credentials via 169.254.169.254 in cloud deployments and enable internal network reconnaissance and injection of attacker-controlled content into LLM tool results.

Mitigation

The source does not state a fix yet. Check the original advisory for updates.

Topics

• Model Context Protocol

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