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CVE-2026-77255

MCP Atlassian: Arbitrary File Read & Exfiltration (Confused Deputy) in JIRA update_issue PUBLISHED

Description (CNA)

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the Jira update_issue attachments argument is converted into local paths and routed to the attachment upload implementation without workspace validation. A caller can make the MCP server read arbitrary local files and attach them to a Jira issue, using the server as a confused deputy to exfiltrate the contents. The advisory traces the vulnerable input and processing flow through jira update_issue, attachments, upload_attachment, and file_path, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

Affected (CNA)

Vendor / productVersions
sooperset / mcp-atlassianaffected < 0.22.0

CWE

CWE-22, CWE-441

References

ADP enrichment

CISA-ADP

No English description supplied.