CVEvulnerability

CVE-2026-77255

8.6 HIGH Published 2026-09-22 Modified 2026-09-29 Official page ↗
Status
Analyzed
Published
2026-09-22
Last modified
2026-09-29
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.6 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Weaknesses
CWE-22, CWE-441

Description

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 configurations

• mcp-atlassian mcp atlassian (< 0.22.0)

Related

Weakness · CWE (2)

  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory weakness
  • CWE-441 Unintended Proxy or Intermediary weakness

References