{"id":"CVE-2026-86044","published":"2026-11-06T21:17:12.297","lastModified":"2026-11-10T20:19:38.707","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.","cvssScore":9.6,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","cwes":["CWE-601"],"vendors":[],"products":[],"references":[{"url":"https://github.com/jupyterlab/jupyterlab-desktop/commit/7f8f64ae796efae77d106612c95f0edd6c5dc273","tags":[]},{"url":"https://github.com/jupyterlab/jupyterlab-desktop/releases/tag/v4.6.2-1","tags":[]},{"url":"https://github.com/jupyterlab/jupyterlab-desktop/security/advisories/GHSA-2mr8-962v-wc67","tags":[]},{"url":"https://github.com/jupyterlab/jupyterlab-desktop/security/advisories/GHSA-2mr8-962v-wc67","tags":[]}],"exploitRefs":[{"url":"https://github.com/jupyterlab/jupyterlab-desktop/commit/7f8f64ae796efae77d106612c95f0edd6c5dc273","tags":[]},{"url":"https://github.com/jupyterlab/jupyterlab-desktop/releases/tag/v4.6.2-1","tags":[]},{"url":"https://github.com/jupyterlab/jupyterlab-desktop/security/advisories/GHSA-2mr8-962v-wc67","tags":[]},{"url":"https://github.com/jupyterlab/jupyterlab-desktop/security/advisories/GHSA-2mr8-962v-wc67","tags":[]}],"hasPoc":true,"ai":{"summary":"JupyterLab Desktop prior to 4.6.2-1 exposed the getServerInfo API to renderers without verifying the origin of the current page, allowing an attacker to exploit a MathJax link in an untrusted notebook to redirect the renderer while retaining access to the preload bridge, then retrieve server credentials and execute arbitrary code via the Jupyter REST API.","exploitability":"Exploitation requires user interaction (clicking a malicious link in a notebook) and relies on a specific chain involving outdated MathJax handling in versions before 4.4.8; users on 4.4.8+ are protected from the first step.","blast_radius":"Successful exploitation grants full remote code execution as the victim user, enabling data theft, lateral movement, or persistence within the local Jupyter environment.","remediation":"Upgrade to JupyterLab Desktop version 4.6.2-1 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["rce","origin-validation-bypass","web","renderer-bridge-abuse"],"model":"garnet-coder","analyzedAt":"2026-11-07T09:58:14.829Z"}}