What is CVE-2026-77258?

CVE-2026-77258 is a high-severity vulnerability in Sooperset Mcp-Atlassian, classified under Path Traversal. CVSS score: 7.7/10. Published 2026-09-22.

How severe is CVE-2026-77258?

High severity. CVSS v3 base score is 7.7 out of 10.

Path Traversal in Sooperset Mcp-Atlassian

CVE-2026-77258

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2026-09-22.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/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

Sooperset Mcp-Atlassian — versions < 0.22.0

Weakness classification (CWE)

CWE-22 — Path Traversal

References

Frequently asked questions

What is CVE-2026-77258?: CVE-2026-77258 is a high-severity vulnerability in Sooperset Mcp-Atlassian, classified under Path Traversal. CVSS score: 7.7/10. Published 2026-09-22.
How severe is CVE-2026-77258?: High severity. CVSS v3 base score is 7.7 out of 10.