Path Traversal in Sooperset Mcp-Atlassian

CVE-2026-77246

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, an HTTP transport deployment with READ_ONLY_MODE=false accepts a request without an Authorization identity and permits attacker-controlled Atlassian service headers, including X-Atlassian-Confluence-Url, to select a public attacker hostname or one allowed by MCP_ALLOWED_URL_DOMAINS. A caller can then invoke confluence_upload_attachment or the Jira attachment variant in src/mcp_atlassian/jira/attachments.py with a server-local file_path and cause the MCP process to send the file to the selected attachment endpoint. This issue is fixed in version 0.22.0.

Vulnerability class: Path Traversal (Directory Traversal)

Published .

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:N/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-2026-77246?
CVE-2026-77246 is a high-severity vulnerability in Sooperset Mcp-Atlassian, classified under Path Traversal. CVSS score: 7.4/10. Published 2026-09-22.
How severe is CVE-2026-77246?
High severity. CVSS v3 base score is 7.4 out of 10.