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Vulnerability record · CVE-2021-32862 · published 18 August 2022

CVE-2021-32862: Jupyter nbconvert cross-site scripting vulnerability

Jupyter · Nbconvert

The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).

5.4 CVSS 3.1 Medium EPSS 1.4% · top 28.9% CWE-79 · Cross-site scripting
5.4CVSS 3.1 base score
1.4%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
7References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/jupyter/nbconvert/security/advisories/GHSA-9jmq-rx5f-8jwq ExploitThird Party Advisory
https://github.com/jupyter/nbviewer/security/advisories/GHSA-h274-fcvj-h2wm Broken Link
https://lists.debian.org/debian-lts-announce/2023/06/msg00003.html Mailing ListThird Party Advisory
https://github.com/jupyter/nbconvert/security/advisories/GHSA-9jmq-rx5f-8jwq ExploitThird Party Advisory
https://github.com/jupyter/nbviewer/security/advisories/GHSA-h274-fcvj-h2wm Broken Link
https://lists.debian.org/debian-lts-announce/2023/06/msg00003.html Mailing ListThird Party Advisory
https://lists.debian.org/debian-lts-announce/2024/09/msg00004.html

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Source: NIST National Vulnerability Database (record CVE-2021-32862), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.