CVEvulnerability

CVE-2026-77248

8.6 HIGH Published 2026-09-22 Modified 2026-09-28 Official page ↗
Status
Analyzed
Published
2026-09-22
Last modified
2026-09-28
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.6 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Weaknesses
CWE-22, CWE-306

Description

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 configurations

• mcp-atlassian mcp atlassian (< 0.22.0)

Related

Weakness · CWE (2)

  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory weakness
  • CWE-306 Missing Authentication for Critical Functionality weakness

References