{"id":"BIT-jupyterlab-2026-42266","summary":"JupyterLab has an Extension Manager API/GUI Policy Discrepancy allowing 3rd party (malicious) extensions install via POST request.","details":"JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From 4.0.0 to 4.5.6, the allow-list of extensions that can be installed from PyPI Extension Manager (allowed_extensions_uris) is not correctly enforced by JupyterLab. The PyPI Extension Manager was not contained to packages listed on the default PyPI index. This vulnerability is fixed in 4.5.7.","aliases":["CVE-2026-42266","GHSA-37w4-hwhx-4rc4","PYSEC-2026-164"],"modified":"2026-09-08T08:47:30.371556422Z","published":"2026-05-15T08:42:28.664Z","database_specific":{"cpes":["cpe:2.3:a:jupyter:jupyterlab:*:*:*:*:*:python:*:*"],"severity":"High"},"references":[{"type":"ADVISORY","url":"https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42266"},{"type":"FIX","url":"https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7"},{"type":"WEB","url":"https://jupyterhub.readthedocs.io/en/5.2.1/explanation/websecurity.html"},{"type":"WEB","url":"https://jupyterlab.readthedocs.io/en/latest/user/extensions.html#extension-manager-implementations"},{"type":"WEB","url":"https://access.redhat.com/security/cve/CVE-2026-42266"},{"type":"WEB","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2477072"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42266.json"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:43038"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:60520"}],"affected":[{"package":{"name":"jupyterlab","ecosystem":"Bitnami","purl":"pkg:bitnami/jupyterlab"},"ranges":[{"type":"SEMVER","events":[{"introduced":"4.0.0"},{"fixed":"4.5.7"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/jupyterlab/BIT-jupyterlab-2026-42266.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}],"schema_version":"1.9.0"}