CVE-2026-77267: Mcp-Atlassian Mcp Atlassian

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url headers are processed by _process_authentication_headers and used to construct Atlassian fetchers without calling validate_url_for_ssrf. A caller who can set these headers can supply an internal or metadata-service URL and cause the server to send requests to that destination, bypassing the incomplete CVE-2026-27826 remediation. This issue is fixed in version 0.22.0.

Affected products

Published 2026-09-22. Last modified 2026-09-29.