CVEvulnerability

CVE-2026-77244

10.0 CRITICAL Published 2026-09-22 Modified 2026-09-29 Official page ↗
Status
Analyzed
Published
2026-09-22
Last modified
2026-09-29
Assigner
[email protected]
CVSS 3.1 ([email protected])
10.0 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Weaknesses
CWE-287, CWE-303, CWE-862

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the HTTP transport accepts requests without a verified user identity and downstream fetcher construction falls back to the operator's globally configured Jira or Confluence credentials. A network client that can reach the MCP endpoint can invoke Atlassian tools as the operator, including read and write operations available to that account. The advisory traces the vulnerable input and processing flow through UserTokenMiddleware, AtlassianOpaqueTokenVerifier, _get_fetcher, and streamable-http, 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 (3)

  • CWE-287 Improper Authentication weakness
  • CWE-303 Incorrect Implementation of Authentication Algorithm weakness
  • CWE-862 Missing Authorization weakness

References