SEPTEMBER 18, 2026
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Case File

CVE-2026-42557

CRITICAL · CVSS 9.6 EPSS 0.35% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2026-05-13 · Last synced 2026-08-04

CyberRota Analysis

This is a critical severity vulnerability with a CVSS score of 9.6. Public exploit code or proof-of-concept references have been detected in its references.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
arbitrary code execution code execution
GitHub PoC Links

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2026-42557
Severity
CRITICAL
CVSS
9.6
EPSS
0.35%

Original NVD Description

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.

Related CVEs

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