CVE-2026-77262: Mcp-Atlassian Mcp Atlassian

High severity, CVSS 8.6. EPSS: 0.5% chance of exploitation in the next 30 days.

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, confluence_upload_attachment accepts an attacker-controlled file_path and does not apply the path restriction added for the earlier download vulnerability. A caller can traverse outside the workspace and upload arbitrary server-readable files to Confluence. The advisory traces the vulnerable input and processing flow through confluence_upload_attachment, file_path, and CVE-2026-27825, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Affected products

Published 2026-09-22. Last modified 2026-09-29.