CVE-2026-77248

HIGHCVSS 8.6/10

Last modified

CVE-2026-77248 is a high-severity vulnerability rated 8.6/10 on the CVSS scale. 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.

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.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
soopersetmcp-atlassian< 0.22.0

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-77248?
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.
How severe is CVE-2026-77248?
CVE-2026-77248 has a CVSS score of 8.6/10 (HIGH severity).
How do I fix CVE-2026-77248?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST