CVE-2026-77243

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, ENABLED_TOOLS and TOOLSETS are applied when tools are listed but are not rechecked when a tools/call request is dispatched. A client that knows a hidden tool name can directly invoke excluded read, write, or delete tools despite the operator's configured least-privilege restrictions. The advisory traces the vulnerable input and processing flow through ENABLED_TOOLS, TOOLSETS, tools/list, tools/call, and _call_tool_mcp, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

  • Published Sep 22, 2026
  • CVSS 8.8 high
  • 0.3% chance of exploitation in the next 30 days (EPSS)
  • Public exploit code is available
  • A fix is available

Affected software

CVE-2026-77243 at the National Vulnerability Database