CVE-2026-77254: mcp-atlassian mcp_atlassian

CVSS 9.1 (critical) · published 2026-09-22

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, requests to the HTTP MCP endpoint without a per-user identity are allowed to reach tool handlers, which then use globally configured Jira or Confluence credentials. A network caller can perform operations with the operator account's permissions unless the deployment has an independent authentication boundary. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, _get_fetcher, and global credentials, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Affected products (NVD): mcp-atlassian mcp_atlassian

Fixed in (NVD): 0.22.0

Weakness: CWE-306

Source: NVD CVE-2026-77254

References

• https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460
• https://github.com/sooperset/mcp-atlassian/pull/1448
• https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0
• https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hx
• https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-vc8m-84rp-53hx

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