CVE-2026-77265
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.
How to fix
- mcp-atlassian mcp_atlassian0.22.0 or later
- mcp-atlassian0.22.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mcp-atlassian mcp_atlassian | v < 0.22.0 | 0.22.0 |
| mcp-atlassianPyPI | v < 0.22.0 | 0.22.0 |
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Attack Surface Management
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