{"id":"CVE-2026-42266","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-42266","generatedAt":"2026-10-28T04:46:15.741Z","title":"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.","description":"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.","published":"2026-05-13T16:16:47.000Z","lastModified":"2026-08-28T16:17:59.000Z","status":"Modified","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-88","CWE-602"],"affected":["jupyter/jupyterlab"],"epss":{"score":0.05652,"percentile":0.92927,"date":"2026-10-27","history":[{"date":"2026-10-25","score":0.05652,"percentile":0.92912}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (5.65%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/jupyterlab/jupyterlab/releases/tag/v4.5.7","tags":["Patch","Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-37w4-hwhx-4rc4","tags":["Mitigation","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://jupyterhub.readthedocs.io/en/5.2.1/explanation/websecurity.html","tags":["Product"],"source":"security-advisories@github.com"},{"url":"https://jupyterlab.readthedocs.io/en/latest/user/extensions.html#extension-manager-implementations","tags":["Product"],"source":"security-advisories@github.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:43038","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:60520","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-42266","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2477072","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42266.json","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-42266","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}