CVE-2021-32862: nbconvert vulnerable to cross-site scripting (XSS) via multiple exploit paths

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2022-08-18 · updated 2026-06-17
Weakness: CWE-79

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).

Affected products

Debian Linux: 10.0
jupyter nbconvert: through 6.2.0

References

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

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