GitHub Advisoryadvisory · PyPI

GHSA-p43p-whwx-q52h JupyterHub has Unauthenticated Denial of Service via Unbounded Username Logging on Failed Login

MEDIUM Published 2026-08-25 Modified 2026-08-25 Official page ↗
Aliases
CVE-2026-54338
Ecosystem
PyPI
Packages
jupyterhub
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weaknesses
CWE-400
Reviewed
2026-08-25

Affected packages

• PyPI jupyterhub: < 5.5.0 → fixed in 5.5.0

Description

Impact Invalid input to login resulted in unbounded logging output. Only form-based Authenticators (the default PAM Authenticator, but not the more widely used OAuthenticator) are affected. Patches Upgrade to 5.5.0. Workarounds Use an Authenticator that doesn't use a login form, such as OAuthenticator.

Related

Alias · CVE (1)

  • CVE-2026-54338 JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. vulnerability

Weakness · CWE (1)

  • CWE-400 Uncontrolled Resource Consumption weakness

References