CVE-2026-40171
Description
A flaw was found in Jupyter Notebook and JupyterLab. A stored cross-site scripting (XSS) vulnerability in the help command linker can be exploited by an attacker who crafts a malicious notebook file. When a user interacts with this file, the XSS is triggered, allowing the attacker to steal authentication tokens. Successful exploitation can lead to a complete takeover of the Jupyter session, enabling arbitrary code execution and information disclosure.
Statement
This is an Important flaw in Jupyter Notebook and JupyterLab, enabling a stored cross-site scripting (XSS) attack. An attacker can craft a malicious notebook that, with a single user click, can steal authentication tokens and fully compromise the Jupyter session, leading to arbitrary code execution and information disclosure. This impacts Red Hat OpenShift AI and Migration Toolkit for Applications.
Mitigation
To reduce the risk of exploitation, disable the affected help extensions in Jupyter Notebook and JupyterLab, or set the `allowCommandLinker` option to `false` within the sanitizer configuration. Consult the Jupyter documentation for specific instructions on modifying these settings. Disabling these features may affect the availability of certain help functionalities.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.8 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | Required | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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