Path Traversal in Sooperset Mcp-Atlassian

CVE-2026-77253

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, Jira and Confluence attachment upload tools accept arbitrary local filesystem paths and send the selected bytes to Atlassian. In HTTP or multi-user deployments, a caller can cross the client-to-server filesystem boundary and disclose configuration, credentials, mounted secrets, or other files readable by the MCP process. The advisory traces the vulnerable input and processing flow through jira_upload_attachment, confluence_upload_attachment, file_path, and server-local filesystem, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Vulnerability class: Path Traversal (Directory Traversal)

Published .

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-77253?
CVE-2026-77253 is a high-severity vulnerability in Sooperset Mcp-Atlassian, classified under Path Traversal. CVSS score: 7.1/10. Published 2026-09-22.
How severe is CVE-2026-77253?
High severity. CVSS v3 base score is 7.1 out of 10.