---
title: JupyterLab Desktop: malicious Connect-to-server URL → XSS → RCE (GHSA-vrj4 / CVE-2026-102530 family) — upgrade to 4.6.2-1 | ctxsec
url: https://ctxsec.com/items/jupyterlab-desktop-ghsa-vrj4-xss-rce-connect-url-4-6-2-1
description: "JupyterLab Desktop before v4.6.2-1 inserted user-supplied remote-server URLs into the Welcome/Remote Server UI without encoding. A crafted URL becomes XSS in the Welcome renderer, which has privileged Electron IPC (sendMessageToMain) sufficient for arbitrary command injection \u2014 full RCE as the desktop user after the victim pastes/connects to the malicious URL (GHSA-vrj4-r4fw-9rfh, CVSS 4.0 critical). Sibling advisory GHSA-2mr8-962v-wc67 covers a one-click MathJax/token-leak RCE path. NVD received CVE-2026-102530 (and related Desktop CVEs) on Nov 6 for the July 4.6.2-1 security release. Affected: Desktop \u2264 v4.2.5-1. No complete workaround beyond upgrading and refusing unsolicited remote-server URLs."
status: "official (jupyterlab/jupyterlab-desktop GHSA-vrj4-r4fw-9rfh Critical; fixed in v4.6.2-1, Jul 2026); CVE-2026-102530 and related Desktop CVEs received by NVD on Nov 6"
published: 2026-11-06
---

> JupyterLab Desktop before v4.6.2-1 inserted user-supplied remote-server URLs into the Welcome/Remote Server UI without encoding. A crafted URL becomes XSS in the Welcome renderer, which has privileged Electron IPC (sendMessageToMain) sufficient for arbitrary command injection — full RCE as the desktop user after the victim pastes/connects to the malicious URL (GHSA-vrj4-r4fw-9rfh, CVSS 4.0 critical). Sibling advisory GHSA-2mr8-962v-wc67 covers a one-click MathJax/token-leak RCE path. NVD received CVE-2026-102530 (and related Desktop CVEs) on Nov 6 for the July 4.6.2-1 security release. Affected: Desktop ≤ v4.2.5-1. No complete workaround beyond upgrading and refusing unsolicited remote-server URLs.

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official (jupyterlab/jupyterlab-desktop GHSA-vrj4-r4fw-9rfh Critical; fixed in v4.6.2-1, Jul 2026); CVE-2026-102530 and related Desktop CVEs received by NVD on Nov 6

2026-11-06

### JupyterLab Desktop: malicious Connect-to-server URL → XSS → RCE (GHSA-vrj4 / CVE-2026-102530 family) — upgrade to 4.6.2-1

- **Do now:** upgrade JupyterLab Desktop to **4.6.2-1** or later on every analyst laptop; inventory older per-user installs that missed the July security release.
- Only connect to remote Jupyter URLs you obtained out-of-band from a trusted operator.
- Related: GHSA-2mr8-962v-wc67 (token leak → RCE) also fixed in 4.6.2-1; macOS TCC bypass pair is medium and needs local code exec first.

Sources: [GHSA-vrj4-r4fw-9rfh: malicious server URL → XSS → RCE](https://github.com/jupyterlab/jupyterlab-desktop/security/advisories/GHSA-vrj4-r4fw-9rfh) · [GHSA-2mr8-962v-wc67: one-click server token leak → RCE](https://github.com/jupyterlab/jupyterlab-desktop/security/advisories/GHSA-2mr8-962v-wc67) · [JupyterLab Desktop v4.6.2-1 release](https://github.com/jupyterlab/jupyterlab-desktop/releases/tag/v4.6.2-1)