CVE-2026-77248
MCP Atlassian: Unauthenticated arbitrary local file read via upload_attachment file_path, chained with missing auth on streamable-http transport
Impact
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the streamable HTTP transport accepts requests without a user identity and falls back to operator credentials, while upload_attachment accepts an unrestricted file_path. An unauthenticated network caller can read files available to the MCP process, upload them to an attacker-selected Jira issue or Confluence page, and retrieve the contents. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, upload_attachment, file_path, and _get_fetcher, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | mcp-atlassian | < 0.22.0 | 0.22.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mcp-Atlassian | Mcp Atlassian | before 0.22.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-cc5h-2pwp-pvcc
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-cc5h-2pwp-pvcc
- https://github.com/sooperset/mcp-atlassian/pull/1448
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0