CVE-2026-77267
Medium
Description
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the X-Atlassian-Jira-Url and X-Atlassian-Confluence-Url headers are processed by _process_authentication_headers and used to construct Atlassian fetchers without calling validate_url_for_ssrf. A caller who can set these headers can supply an internal or metadata-service URL and cause the server to send requests to that destination, bypassing the incomplete CVE-2026-27826 remediation. This issue is fixed in version 0.22.0.
SeverityMedium
CVSS6.5
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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