MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to version 0.17.0, the `confluence_download_attachmen…

CVE-2026-27825 affects MCP Atlassian, a Model Context Protocol server for Confluence and Jira products. Prior to version 0.17.0, the confluence_download_attachment tool lacks directory boundary enforcement in the download_path parameter. Attackers can exploit this to write arbitrary content to any server path with write access. The vulnerability enables arbitrary code execution by controlling both destination and content through malicious Confluence attachments. Examples include writing cron entries to /etc/cron.d/ for scheduled code execution. Version 0.17.0 resolves the issue.