CVE-2026-77248 (GCVE-0-2026-77248)

Vulnerability from cvelistv5 – Published: 2026-09-22 18:49 – Updated: 2026-09-24 15:23
VLAI
Title
MCP Atlassian: Unauthenticated arbitrary local file read via upload_attachment file_path, chained with missing auth on streamable-http transport
Summary
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.
SSVC
Exploitation: poc Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-24 15:23 UTC
CWE
  • CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  • CWE-306 - Missing Authentication for Critical Function
Impacted products
Vendor Product Version CPE status
sooperset mcp-atlassian Affected: < 0.22.0
guessed Create a notification for this product.
Show details on NVD website

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