Quick answers
- Is CVE-2026-123291 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-123291 being exploited in the wild.
- How severe is CVE-2026-123291?
- Medium severity, with a CVSS score of 4.3, published 6 November 2026.
- Which products and versions are affected?
- Jetbrains Datalore before 2026.4.
- Is there a fix for CVE-2026-123291?
- Yes: fixed in Datalore 2026.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-123291 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-123291?
- Check whether you run Jetbrains Datalore at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: Datalore 2026.4
Technical details
Datalore before version 2026.4 contains improper ownership validation in its API or access control logic, allowing an authenticated attacker to access notebook runs and issues belonging to other workspaces. The vulnerability likely requires network access and valid credentials but does not appear to require elevated privileges or user interaction. A successful exploit results in unauthorized information disclosure of workspace data.
Affected products
- JetBrains Datalore before 2026.4
Timeline
- 2026-11-06: disclosed