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CVE PROGRAM SOURCE RECORD5.9 Medium

CVE-2026-77265

MCP Atlassian: SSRF via DNS Rebinding in Header-Based Authentication Flow

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, header-supplied Jira or Confluence URLs are resolved and validated before the HTTP client resolves the hostname again for the connection. An unauthenticated caller can use a DNS-rebinding hostname that returns a public address during validation and an internal address during connection, causing requests to internal or metadata services. The advisory traces the vulnerable input and processing flow through X-Atlassian-Jira-Url, X-Atlassian-Confluence-Url, validate_url_for_ssrf, and DNS rebinding, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

sooperset mcp-atlassian

  • < 0.22.0affected

References