https://vulnerability.circl.lu/rss/recent/all/10 Most recent entries from all 2026-10-02T10:57:15.232874+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent entries. https://vulnerability.circl.lu/vuln/cve-2026-77248 CVE-2026-77248 — MCP Atlassian: Unauthenticated arbitrary local file read via upload_attachment file_path, chained with missing auth on… 2026-10-02T10:57:15.235281+00:00

Affected: sooperset mcp-atlassian

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.

 https://vulnerability.circl.lu/vuln/pysec-2026-4089 PYSEC-2026-4089 — MCP Atlassian: Unauthenticated arbitrary local file read via upload_attachment file_path, chained with missing auth on… 2026-10-02T10:57:15.235393+00:00

Affected: PyPI: mcp-atlassian

### Summary 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.

### Details **Missing authentication (transport):** - streamable-http binds `0.0.0.0` by default (`src/mcp_atlassian/__init__.py:151`). - The OAuth-proxy auth provider is opt-in (`ATLASSIAN_OAUTH_PROXY_ENABLE`, default false), so `main_mcp` is built with `auth=None` (`src/mcp_atlassian/servers/main.py:724-731, 813-817`). - `UserTokenMiddleware._parse_auth_header` sets `auth_validation_error` only for a *malformed* Authorization header; a request with **no** Authorization header passes through (`main.py:416-446, 582-595`). - `_get_fetcher` then falls through to the global credential fallback using the operator's `.env` Atlassian token (`src/mcp_atlassian/servers/dependencies.py:644-676`). `check_write_access` gates only on read-only mode, not auth → read **and** write tools reachable.

**Arbitrary file read (sink):** - `upload_attachment`'s `file_path` flows unsanitized into `open(file_path,…