cyfenced.com →

[ CVE-2026-77270 · Published 22 Sep 2026 ]

MCP Atlassian: Arbitrary File Read via Upload Attachment Tools

CVSS 6.5 EPSS <1%Fix available

[ Why it matters ]Priority signals

  • Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the Jira and Confluence attachment upload tools treat caller-controlled file_path values as trusted server-local paths. The server opens the selected file and uploads it to an Atlassian issue or page, allowing an MCP caller with upload access to disclose any file readable by the server process. The advisory traces the vulnerable input and processing flow through confluence_upload_attachment, jira_upload_attachment, file_path, and open(file_path, "rb"), which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

[ Fixes ]Fixes and patches

  • mcp-atlassian 0.22.0Fixed version · GitHub Advisories · pip package mcp-atlassian: upgrade to 0.22.0 or later (affected < 0.22.0)

[ Packages ]Affected open-source packages

[ References ]References