Vulnerability Description
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, an HTTP transport deployment with READ_ONLY_MODE=false accepts a request without an Authorization identity and permits attacker-controlled Atlassian service headers, including X-Atlassian-Confluence-Url, to select a public attacker hostname or one allowed by MCP_ALLOWED_URL_DOMAINS. A caller can then invoke confluence_upload_attachment or the Jira attachment variant in src/mcp_atlassian/jira/attachments.py with a server-local file_path and cause the MCP process to send the file to the selected attachment endpoint. This issue is fixed in version 0.22.0.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mcp-Atlassian | Mcp Atlassian | < 0.22.0 |
Related Weaknesses (CWE)
References
- https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c28Patch
- https://github.com/sooperset/mcp-atlassian/pull/1448Issue TrackingPatch
- https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0Release Notes
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v7ExploitVendor Advisory
- https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-wv8v-v4c5-v7ExploitVendor Advisory
FAQ
What is CVE-2026-77246?
CVE-2026-77246 is a vulnerability with a CVSS score of 7.4 (HIGH). MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, an HTTP transport deployment with READ_ONLY_MODE=false accepts a request without a...
How severe is CVE-2026-77246?
CVE-2026-77246 has been rated HIGH with a CVSS base score of 7.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-77246?
Check the references section above for vendor advisories and patch information. Affected products include: Mcp-Atlassian Mcp Atlassian.