What’s Vulnerable › Vulnerabilities

CVE-2021-32798: Failure to Sanitize Special Elements into a Different Plane (Special Element Injection) in notebook

• Severity: critical (CVSS 9.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.1% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-08-09 · updated 2026-06-17
• Weakness: CWE-79

Description

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.

Affected products

• jupyter notebook: from 5.7.0 before 5.7.11; 6.4.0 — fixed in 5.7.11

How to fix

Upgrade to a fixed version: jupyter notebook 5.7.11. Check the vendor advisory for mitigations.

References

• https://github.com/jupyter/notebook/commit/79fc76e890a8ec42f73a3d009e44ef84c14ef0d5
• https://github.com/jupyter/notebook/security/advisories/GHSA-hwvq-6gjx-j797
• https://github.com/jupyter/notebook/commit/79fc76e890a8ec42f73a3d009e44ef84c14ef0d5
• https://github.com/jupyter/notebook/security/advisories/GHSA-hwvq-6gjx-j797

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