CVE-2026-42557
criticaljupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture.
Vendor / product: Jupyter — jupyterlab
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-mqcg-5x36-vfcg security-advisories@github.com
- https://access.redhat.com/errata/RHSA-2026:43038 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/errata/RHSA-2026:60520 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://access.redhat.com/security/cve/CVE-2026-42557 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://bugzilla.redhat.com/show_bug.cgi?id=2477086 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42557.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c