Description

In JetBrains Datalore before 2026.4 private notebook files could be downloaded without authentication via published interactive reports

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.9",
  "pubDate": "2026-11-06T11:17:07.177Z",
  "pubdate": "2026-11-06T11:17:07.177Z",
  "executiveSummary": "A broken access control vulnerability exists in JetBrains Datalore prior to version 2026.4, allowing unauthenticated users to download private notebook files.\nThe vulnerability resides within the interactive report publication feature, which fails to properly enforce authorization checks when requests are directed at underlying private notebook resources.\nThis flaw allows any network-adjacent or remote attacker to bypass authentication mechanisms and exfiltrate sensitive data contained within private notebooks without requiring valid user credentials.\nThe risk implication is significant, as the exposure of proprietary code, credentials, or sensitive research data stored in notebooks can lead to complete data breaches and loss of intellectual property.\nExploitation requires no special privileges, as the vulnerability is accessible to unauthenticated actors interacting with the public-facing report publishing infrastructure.",
  "technicalDetails": "The root cause of this vulnerability is an improper authorization implementation within the JetBrains Datalore report publishing subsystem. Specifically, the application fails to validate the requester's identity or access permissions when handling download requests for notebook files linked to published interactive reports.\nUnder normal operating conditions, a notebook marked as private should be isolated from the public-facing components of the Datalore environment. However, the interactive report publication mechanism incorrectly exposes the file-download endpoints for these private notebooks to the web server's request handlers.\nThe attack flow follows a predictable pattern where an attacker identifies the URI associated with a published report. By manipulating or observing the underlying resource requests associated with the report, the attacker can craft a direct HTTP request to the Datalore server. Because the server does not perform an authentication token validation or an ownership check prior to serving the file, the server returns the contents of the private notebook file directly in the HTTP response body.\nThis behavior indicates a failure in the API gateway or the backend controller logic responsible for validating access control lists (ACLs). The vulnerability effectively negates the private status of the notebook, treating it as a public asset whenever the publishing feature is active or misconfigured.\nThe affected versions include all releases of JetBrains Datalore prior to 2026.4. The exposure is persistent across all deployments where the product is accessible via the network. Because the vulnerability exists at the application layer, it can be exploited regardless of the underlying operating system, provided the vulnerable version of Datalore is running.\nPost-exploitation impact includes the full disclosure of notebook contents, which often include API keys, database connection strings, sensitive environment variables, and confidential analytical models. Once the content is exfiltrated, there are no forensic logs within the notebook environment that would necessarily alert the user to an unauthorized access event, making detection difficult without extensive server-side request logging and traffic analysis."
}