CVE-2026-77274 — MCP Atlassian: SSRF Protection Bypass
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 b…
Published: 2026-09-22 · CVSS: 8.8 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7