CVE-2026-77274
High
Description
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.
SeverityHigh
CVSS8.2
Exploit probability—
ProductMcp-atlassian Mcp Atlassian
PublishedSep 22, 2026
First seenSep 22, 2026
Weakness typeCWE-918Server-side request forgery (SSRF)
How to fix
Update
- 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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