https://db.gcve.eu/rss/recent/all/10 Most recent entries from all 2026-10-01T10:23:38.459852+00:00 Vulnerability-Lookup info@gcve.eu python-feedgen Contains only the most 10 recent entries. https://db.gcve.eu/vuln/fkie_cve-2026-77255 fkie_cve-2026-77255 2026-10-01T10:23:38.488726+00:00

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.

 https://db.gcve.eu/vuln/ghsa-2xj6-xx86-cwwc GHSA-2xj6-xx86-cwwc — MCP Atlassian: Arbitrary File Read & Exfiltration (Confused Deputy) in JIRA update_issue 2026-10-01T10:23:38.488810+00:00

Affected: PyPI: mcp-atlassian

### Summary A critical Confused Deputy (Arbitrary File Read & Exfiltration) vulnerability in the Atlassian MCP server (Python) allows an AI agent to exfiltrate sensitive host files and environment secrets. By providing absolute system paths to the attachments parameter of the update_issue tool, an agent can force the privileged MCP process to read and upload any file it has access to—including its own environment variables and host configuration—directly to a Jira ticket.

### Details The vulnerability is located in the update_issue tool handler. The attachments parameter accepts a list of file paths that are passed directly to the Jira API's upload method without any sanitization or validation.

Specifically, the implementation fails to: 1.  Restrict paths to a safe workspace: It accepts absolute paths starting with /. 2.  Prevent directory traversal: It does not filter for ../ sequences. 3.  Validate ownership: It allows the process to read system-level files (like /proc/self/environ) that the calling agent is normally forbidden from accessing due to sandbox restrictions.

Because the MCP server typically runs with higher privileges than the AI agent (holding the JIRA_API_TOKEN and having wider filesystem access), it acts as a "Confused Deputy," performing exfiltration on behalf of a restricted agent.

### PoC To reproduce the vulnerability in an environment where the agent is sandboxed (e.g., as a restricted Unix user) but the MCP server has host-level access:

1.  Exfil…