CVE-2026-86044
JupyterLab Desktop: One-Click Jupyter Server Token Leak leading to Remote Code Execution
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
JupyterLab Desktop is the cross-platform desktop application for JupyterLab. Prior to 4.6.2-1, JupyterLab Desktop exposed getServerInfo to the renderer without confirming that the current page still had the local Jupyter server origin. In a local managed session using JupyterLab before 4.4.8, an attacker can place a crafted MathJax link in an untrusted notebook. If a victim opens the notebook and clicks the link, the existing renderer navigates to an attacker-controlled site while retaining access to the preload bridge. The site can call getServerInfo to obtain the local server URL and authentication token, then use the Jupyter REST API to create and trust a notebook that executes arbitrary code as the victim. Users whose environment already uses JupyterLab 4.4.8 or later are unaffected because the corrected link handling breaks the first step of the chain. This vulnerability is fixed in 4.6.2-1.
Timeline
ID reserved
By GitHub_M
- 2 months later
· 2 months later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical9.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | Critical9.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.31% · top 76% of all CVEs (7 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.6.
Weakness
Affected products
jupyterlab · jupyterlab-desktop
- affected < 4.6.2-1
References (3)
- https://github.com/jupyterlab/jupyterlab-desktop/security/advisories/GHSA-2mr8-962v-wc67 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/jupyterlab/jupyterlab-desktop/commit/7f8f64ae796efae77d106612c95f0edd6c5dc273 (opens in a new tab)x_refsource_MISC
- https://github.com/jupyterlab/jupyterlab-desktop/releases/tag/v4.6.2-1 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-86044)Record last updated .