CVE-2026-42557
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
Summary
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.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| jupyterlab | jupyterlab | < 4.5.7 | affected |
| jupyter | notebook | >= 7.0.0, < 7.5.6 | affected |
Weaknesses
- CWE-79: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: no
- Technical Impact: total
jupyterlab: JupyterLab: Arbitrary code execution via deceptive button in HTML output
Additional References
- https://access.redhat.com/security/cve/CVE-2026-42557
- https://bugzilla.redhat.com/show_bug.cgi?id=2477086
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42557.json
References
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