What’s Vulnerable › Vulnerabilities

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

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-02-25 · updated 2026-06-17
• Weakness: CWE-347

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.

Affected products

• jupyter Lti Jupyterhub Authenticator: 1.3.0

References

• https://github.com/jupyterhub/ltiauthenticator/blob/3feec2e81b9d3b0ad6b58ab4226af640833039f3/ltiauthenticator/lti13/validator.py#L122-L164
• https://github.com/jupyterhub/ltiauthenticator/blob/main/CHANGELOG.md#140---2023-03-01
• https://github.com/jupyterhub/ltiauthenticator/security/advisories/GHSA-mcgx-2gcr-p3hp

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