CVE-2026-77249

Medium

Description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, JiraUserMixin._lookup_user_by_permissions uses the module-level requests.get function instead of the fetcher's protected session. A caller-controlled public Jira URL can redirect that unhooked request to an internal address, bypassing the redirect checks added for CVE-2026-27826. The advisory traces the vulnerable input and processing flow through JiraUserMixin._lookup_user_by_permissions, requests.get, self.jira._session.get, and _make_ssrf_safe_hook, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

SeverityMedium
CVSS5.3
Exploit probability—
ProductMcp-atlassian Mcp Atlassian
PublishedSep 22, 2026
First seenSep 22, 2026

How to fix

Update
  • mcp-atlassian mcp_atlassian0.22.0 or later
  • mcp-atlassian0.22.0 or later

Affected products

ProductAffected versionsFixed in
mcp-atlassian mcp_atlassianv < 0.22.00.22.0
mcp-atlassianPyPIv < 0.22.00.22.0

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