CVE-2021-32797

JupyterLab: XSS due to lack of sanitization of the action attribute of an html <form>

CRITICAL

9.6

CVSS Score

Published: August 9, 2021 at 08:45 PM UTC

Updated: June 17, 2026 at 03:53 AM UTC

2 products affected across 2 vendorsJupyterlabJupyterlab

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Severity

CRITICAL9.6

Exploit prediction

EPSS 3%

Description

JupyterLab is a user interface for Project Jupyter which will eventually replace the classic Jupyter Notebook. In affected versions untrusted notebook can execute code on load. In particular JupyterLab doesn’t sanitize the action attribute of html `<form>`. Using this it is possible to trigger the form validation outside of the form itself. This is a remote code execution, but requires user action to open a notebook.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Jupyterlab · Jupyter

95%

v < 1.2.212.0.0 ≤ v < 2.2.102.3.0 ≤ v < 2.3.23.0.0 ≤ v < 3.0.173.1.0 ≤ v < 3.1.4

Affected range stops below 1.2.21, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.2.10, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.3.2, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.0.17, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.1.4, so it looks safe — our inference, not a vendor statement

Jupyterlab · Jupyterlab

60%

v < 1.2.1v < 2.2.10v < 2.3.2v < 3.0.17v < 3.1.4

Affected range stops below 1.2.1, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.2.10, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.3.2, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.0.17, so it looks safe — our inference, not a vendor statement

Affected range stops below 3.1.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (2)

x_refsource_MISCExploitThird Party Advisory

Source: [email protected]

https://github.com/jupyterlab/jupyterlab/commit/504825938c0abfa2fb8ff8d529308830a5ae42ed

x_refsource_CONFIRMThird Party Advisory

Source: [email protected]

https://github.com/jupyterlab/jupyterlab/security/advisories/GHSA-4952-p58q-6crx

CVSS

9.6CRITICAL[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: REQUIRED
Scope: CHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-79

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