CVE-2026-77274
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, validate_url_for_ssrf has a backslash authority confusion because it interprets the authority differently from the Requests connection layer in the header-based Jira and Confluence URL authentication flow. A crafted URL can validate as an external hostname while the HTTP client connects to an internal host, permitting server-side requests to protected network resources. This issue is fixed in version 0.22.0.
- Published Sep 22, 2026
- CVSS 8.8 high
- 0.3% chance of exploitation in the next 30 days (EPSS)
- Public exploit code is available
- A fix is available