fkie_cve-2026-77269

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the remediation for CVE-2026-27825 protects download destinations but does not constrain source paths used by attachment uploads. A caller can provide an absolute or traversal file_path and cause the server to upload the selected local file. The advisory traces the vulnerable input and processing flow through 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.

GHSA-h7wj-5v37-59r2 — MCP Atlassian: Path traversal in upload_attachment allows arbitrary file read (incomplete fix for CVE-2026-27825)

Affected: PyPI: mcp-atlassian

### Summary

The `confluence_upload_attachment` and `confluence_upload_attachments` MCP tools accept a `file_path` parameter and do not validate that the path is confined to an allowed directory before opening the file. An attacker who can call these tools can read any file accessible to the MCP server process (SSH keys, .env files, API credentials) and exfiltrate it by uploading it to Confluence.

Note: The Jira `upload_attachment` mixin method in `jira/attachments.py` has the same missing validation, but it is NOT registered as an MCP tool in `servers/jira.py` and is therefore not currently reachable via MCP. It should still be patched to prevent future exposure if Jira upload tools are added.

This is an incomplete fix for CVE-2026-27825. That CVE was patched by adding `validate_safe_path()` to download operations (v0.17.0). The same protection was not applied to upload operations.

### Details

`validate_safe_path()` is imported in both `confluence/attachments.py` and `jira/attachments.py` and is correctly called in all download functions. It is absent from the Confluence upload functions (which are exposed as MCP tools) and from the Jira upload mixin methods (which are not currently registered as MCP tools but should still be patched).

**Download (protected — correctly patched):** ```python # confluence/attachments.py:222-223 validate_safe_path(target_path) # resolves symlinks + checks is_relative_to(cwd) ```

**Upload (vulnerable — not patched):** ```python # conflue…

Most recent entries from all

fkie_cve-2026-77269

GHSA-h7wj-5v37-59r2 — MCP Atlassian: Path traversal in upload_attachment allows arbitrary file read (incomplete fix for CVE-2026-27825)