CVE-2023-25574: Jupyter Lti Jupyterhub Authenticator

Critical severity, CVSS 9.8. EPSS: 0.4% chance of exploitation in the next 30 days.

`jupyterhub-ltiauthenticator` is a JupyterHub authenticator for learning tools interoperability (LTI). LTI13Authenticator that was introduced in `jupyterhub-ltiauthenticator` 1.3.0 wasn't validating JWT signatures. This is believed to allow the LTI13Authenticator to authorize a forged request. Only users that has configured a JupyterHub installation to use the authenticator class `LTI13Authenticator` are affected. `jupyterhub-ltiauthenticator` version 1.4.0 removes LTI13Authenticator to address the issue. No known workarounds are available.

Affected products

• Jupyter Lti Jupyterhub Authenticator: version 1.3.0 only

Published 2025-02-25. Last modified 2026-06-17.