CVE-2023-25574 JupyterHub's LTI13Authenticator: JWT signature not validated

Critical 10.0 Published 25 Feb 2025 Updated 25 Feb 2025

Attackers can forge LTI requests to bypass authentication in JupyterHub if the LTI13Authenticator is configured, allowing unauthorized access.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2023-25574?

CVE-2023-25574 is a critical authentication bypass vulnerability in jupyterhub ltiauthenticator, published on 25 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

`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.

Weakness: CWE-347

Which versions are affected by CVE-2023-25574?

3 open source packages ship an affected version, including jupyterhub-ltiauthenticator. It affects 1 product.

Package	Affected	Fixed in
`jupyterhub-ltiauthenticator` PyPI	All versions to `1.3.0`	None
`jupyterhub-ltiauthenticator` PyPI	From `1.3.0`	`1.4.0`
`jupyterhub-ltiauthenticator` PyPI	From `1.3.0`	`1.4.0`

Products include Jupyter Lti Jupyterhub Authenticator.

How do I fix CVE-2023-25574?

Upgrade jupyterhub-ltiauthenticator to 1.4.0 or later.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2023-25574 being exploited?

There is no known exploitation of CVE-2023-25574 in the wild and no public exploit code.

CVE-2026-34052 LTI JupyterHub Authenticator: Unbounded Memory Growth via Nonce Storage (Denial of Service) Medium 5.9

Sources

Also known as GHSA-mcgx-2gcr-p3hp, PYSEC-2025-120.