CVE-2026-77248: MCP Atlassian: Unauthenticated arbitrary local file read via upload_attachment file_path, chained with missing auth on streamable-http transport
In the documented multi-user HTTP deployment (--transport streamable-http with global operator Atlassian credentials), sooperset/mcp-atlassian exposes all tools to unauthenticated network clients, and the upload_attachment tool reads an attacker-supplied file_path with no path validation. Chained, an unauthenticated network attacker reads arbitrary files on the MCP server host (e.g. /proc/self/environ → the operator’s Atlassian API token + .env secrets, ~/.ssh/id_rsa, /etc/passwd) by uploading them to an attacker-chosen page/issue and reading them back.
References
- github.com/advisories/GHSA-cc5h-2pwp-pvcc
- github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
- github.com/sooperset/mcp-atlassian/pull/1448
- github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0
- github.com/sooperset/mcp-atlassian/security/advisories/GHSA-cc5h-2pwp-pvcc
- nvd.nist.gov/vuln/detail/CVE-2026-77248
Code Behaviors & Features
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