CVE-2026-77262

MCP Atlassian: Path Traversal / Arbitrary File Read in confluence_upload_attachment MCP tool (incomplete fix of CVE-2026-27825)

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, confluence_upload_attachment accepts an attacker-controlled file_path and does not apply the path restriction added for the earlier download vulnerability. A caller can traverse outside the workspace and upload arbitrary server-readable files to Confluence. The advisory traces the vulnerable input and processing flow through confluence_upload_attachment, file_path, and CVE-2026-27825, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Affected

sooperset · mcp-atlassian

CVSS v3.1 GITHUB

8.6 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

EPSS

0.49% chance of exploitation in the next 30 days, 41st percentile

Published

2026-09-22

Updated

2026-09-28

Proof-of-concept exploits (2)

• advisories/GHSA-p6hp-93wp-fh6p
• romain-deperne/CVE-2026-772620★ · 2026-09-07

Security advisories

• sooperset/mcp-atlassian/security/advisories/GHSA-p6hp-93wp-fh6p
• sooperset/mcp-atlassian/pull/1448

References

• CVE Record
• NVD entry

Related

• CVE-2026-27825
• CVE-2026-32247
• CVE-2026-33715
• CVE-2026-33980
• CVE-2026-34160
• CVE-2026-34940