CVE-2026-77266 — MCP Atlassian: Path traversal in upload_attachment allows arbitrary file read and exfiltration via MCP tool call
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, upload_attachment accepts absolute paths and traversal sequ…
Published: 2026-09-22 · CVSS: 6.5 · CVSS 3.1
MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, upload_attachment accepts absolute paths and traversal sequences without constraining the resolved path to the server workspace. An MCP caller with attachment access can read a chosen server-local file and exfiltrate it through Jira or Confluence. The advisory traces the vulnerable input and processing flow through upload_attachment, file_path, and path traversal, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7