Is CVE-2026-86044 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-86044 being exploited in the wild.

How severe is CVE-2026-86044?

Critical severity, with a CVSS score of 9.6, published 6 November 2026.

Which products and versions are affected?

JupyterLab Desktop before 4.6.2-1.

How is CVE-2026-86044 attacked?

It is attacked with local access, in a web application.

Am I affected by CVE-2026-86044?

Check whether you run JupyterLab Desktop 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.

CVE-2026-86044: JupyterLab Desktop server token leak in untrusted notebook

CVE-2026-86044 · Severity: critical · CVSS 9.6 · Published 2026-11-06

JupyterLab Desktop is a cross-platform application that lets users run Jupyter notebooks locally on their computer. An attacker can trick a user into clicking a malicious link in an untrusted notebook, which allows the attacker to steal the local server authentication token and execute arbitrary code on the victim's machine. This vulnerability affects versions before 4.6.2-1; users on JupyterLab 4.4.8 or later are already protected by a different code change.

Technologies: JupyterLab Desktop. Vendors: JupyterLab.

Quick answers

Is CVE-2026-86044 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-86044 being exploited in the wild.
How severe is CVE-2026-86044?: Critical severity, with a CVSS score of 9.6, published 6 November 2026.
Which products and versions are affected?: JupyterLab Desktop before 4.6.2-1.
Is there a fix for CVE-2026-86044?: Yes: fixed in 4.6.2-1. Until then: Users already running JupyterLab 4.4.8 or later are unaffected because corrected link handling blocks the attack chain at its first step. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-86044 attacked?: It is attacked with local access, in a web application.
Am I affected by CVE-2026-86044?: Check whether you run JupyterLab Desktop 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: 4.6.2-1

Users already running JupyterLab 4.4.8 or later are unaffected because corrected link handling blocks the attack chain at its first step.

Technical details

The getServerInfo IPC method trusted only the sender's webContents identity without verifying the current frame origin, allowing an attacker-controlled page loaded inside the lab view to retrieve the server URL and auth token. By placing a crafted MathJax link in a notebook and navigating the renderer off the Jupyter origin while retaining access to the preload bridge, an attacker gains access to sensitive credentials. The fix gates the IPC on the sender frame's current origin matching the server origin and pins the lab view to the server origin for navigation.

Affected products

JupyterLab JupyterLab Desktop before 4.6.2-1

Timeline

2026-11-06: disclosed
2026-07-22: patched

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.