LTI JupyterHub Authenticator does not properly validate JWT Signature
Impact
Only users that has configured a JupyterHub installation to use the authenticator class LTI13Authenticator are influenced.
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 granting access to existing and new user identities.
Patches
None.
Workarounds
None.
References
- This code segment didn't validate a JWT signature.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | jupyterhub-ltiauthenticator | >= 1.3.0, < 1.4.0 | 1.4.0 |
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
- https://nvd.nist.gov/vuln/detail/CVE-2023-25574
- https://github.com/jupyterhub/ltiauthenticator
- https://github.com/pypa/advisory-database/tree/main/vulns/jupyterhub-ltiauthenticator/PYSEC-2025-120.yaml
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H- Weakness (CWE)
CWE-347- Platform
- Python (PyPI)
- Package
jupyterhub-ltiauthenticator- Disclosed
- 25.02.2025
- Updated
- 11.10.2026 12:19
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2025-120 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-mcgx-2gcr-p3hp - CC BY 4.0
Vulnerability history: jupyterhub-ltiauthenticator
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 2
- First → latest
- 02.2025 04.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- Medium 1
Disclosures per year
- 2025: 1
- 2026: 1
-
LTI JupyterHub Authenticator does not properly validate JWT Signature this entry
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