{"id":"UBUNTU-CVE-2026-42557","details":"jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to 4.5.7, JupyterLab's HTML sanitizer allowlists data-commandlinker-command and data-commandlinker-args on button elements, while CommandLinker listens for all click events on document.body and executes the named command without checking whether the element came from trusted JupyterLab UI. A notebook with a pre-saved HTML cell output containing a deceptive button can trigger arbitrary JupyterLab commands - including arbitrary code execution - on a single user click, without any code being submitted for execution by the user. This vulnerability is fixed in 4.5.7.","modified":"2026-06-30T18:18:09.493228660Z","published":"2026-05-13T16:16:00Z","upstream":["CVE-2026-42557"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-42557"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-42557"},{"type":"REPORT","url":"https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-mqcg-5x36-vfcg"}],"affected":[{"package":{"name":"jupyterlab","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/jupyterlab?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.11+ds1+~cs11.25.27-5","4.0.11+ds1+~cs11.25.27-6","4.0.11+ds1+~cs11.25.27-7"],"ecosystem_specific":{"binaries":[{"binary_version":"4.0.11+ds1+~cs11.25.27-7","binary_name":"jupyterlab"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42557.json"}},{"package":{"name":"jupyterlab","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/jupyterlab?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.11+ds1+~cs11.25.27-7","4.0.11+ds1+~cs11.25.27-8","4.0.11+ds1+~cs11.25.27-9"],"ecosystem_specific":{"binaries":[{"binary_name":"jupyterlab","binary_version":"4.0.11+ds1+~cs11.25.27-9"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-42557.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}