Quick answers
- Is CVE-2026-123289 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-123289 being exploited in the wild.
- How severe is CVE-2026-123289?
- Medium severity, with a CVSS score of 5.4, published 6 November 2026.
- Which products and versions are affected?
- Jetbrains Datalore before 2026.4.
- Is there a fix for CVE-2026-123289?
- Yes: fixed in 2026.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-123289 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-123289?
- 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: 2026.4
Technical details
The vulnerability is an improper authorization issue in Datalore's notebook access control mechanism that fails to properly enforce read-only permissions for notebook viewers. Users granted view-only access could escalate privileges to modify files they should only be able to read. The flaw affects versions before 2026.4 and requires an attacker to have legitimate viewer access to the notebook.
Affected products
- JetBrains Datalore before 2026.4
Timeline
- 2026-11-06: disclosed