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Fencer Vulns
critical 10.0

CVE-2021-32798 json

Failure to Sanitize Special Elements into a Different Plane (Special Element Injection) in notebook

published 2021-08-09 5 y ago modified 2026-09-10 1 mo ago also BIT-jupyter-base-notebook-2021-32798 , BIT-jupyter-notebook-2021-32798 , EUVD-2021-0149 , GHSA-hwvq-6gjx-j797 , PYSEC-2021-118

cvss
10.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
2.1%
EPSS 2.1% chance of exploitation in 30 days, percentile 81%
public exploits
0
none known

Summary

The Jupyter notebook is a web-based notebook environment for interactive computing. In affected versions untrusted notebook can execute code on load. Jupyter Notebook uses a deprecated version of Google Caja to sanitize user inputs. A public Caja bypass can be used to trigger an XSS when a victim opens a malicious ipynb document in Jupyter Notebook. The XSS allows an attacker to execute arbitrary code on the victim computer using Jupyter APIs.

Patch / fix

  • pypi notebook 5.7.11, 6.4.1
  • bitnami jupyter-base-notebook 5.7.11, 6.4.1
  • bitnami jupyter-notebook 5.7.11, 6.4.1
  • jupyter notebook 5.7.11
  • jupyter-notebook Debian 14, Debian 13, Debian 12 6.4.3-1

debian advisories DEBIAN-CVE-2021-32798

  • python-notebook Package Hub 15 SP6, openSUSE Leap 15.6 5.7.11-bp156.4.3.1

opensuse advisories openSUSE-SU-2024:0231-1

  • jupyter-notebook Arch Linux 6.4.3-1

arch linux advisories AVG-2267

Exploit prediction

2.11% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/jupyter/notebook/commit/79fc76e890a8ec42f73a3d009e44ef84c14ef0d5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
GitHub 3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
NVD 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P
OSV 3.1 9.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi notebook
<5.7.11
>=6.0.0, <6.4.1
>=5.7.0, <5.7.11
5.7.11
6.4.1
bitnami jupyter-base-notebook
>=5.7.0, <5.7.11
>=6.4.0, <6.4.1
5.7.11
6.4.1
bitnami jupyter-notebook
>=5.7.0, <5.7.11
>=6.4.0, <6.4.1
5.7.11
6.4.1

Affected products

  • jupyter notebook

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-75 Failure to Sanitize Special Elements into a Different Plane
  • CWE-80 Improper Neutralization of Script-Related HTML Tags in a Web Page

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.