CVE-2026-77258: Mcp-Atlassian Mcp Atlassian

High severity, CVSS 7.7. EPSS: 0.3% 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, upload_attachment in src/mcp_atlassian/confluence/attachments.py accepts a caller-controlled file_path and opens the selected server-local file without restricting it to the workspace. A permitted Confluence MCP caller can upload the file as an attachment and disclose data readable by the server process. This issue is fixed in version 0.22.0.

Affected products

• Mcp-Atlassian Mcp Atlassian: before 0.22.0 (fixed in 0.22.0)

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