{"id":"GHSA-mcgx-2gcr-p3hp","summary":"LTI JupyterHub Authenticator does not properly validate JWT Signature","details":"### Impact\n\nOnly users that has configured a JupyterHub installation to use the authenticator class `LTI13Authenticator` are influenced.\n\nLTI13Authenticator 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.\n\n### Patches\n\nNone.\n\n### Workarounds\n\nNone.\n\n### References\n\n- [This code segment](https://github.com/jupyterhub/ltiauthenticator/blob/3feec2e81b9d3b0ad6b58ab4226af640833039f3/ltiauthenticator/lti13/validator.py#L122-L164) didn't validate a JWT signature.","aliases":["CVE-2023-25574","PYSEC-2025-120"],"modified":"2026-06-05T18:00:13.856174005Z","published":"2025-02-25T17:48:34Z","database_specific":{"severity":"CRITICAL","github_reviewed":true,"github_reviewed_at":"2025-02-25T17:48:34Z","nvd_published_at":"2025-02-25T15:15:16Z","cwe_ids":["CWE-347"]},"references":[{"type":"WEB","url":"https://github.com/jupyterhub/ltiauthenticator/security/advisories/GHSA-mcgx-2gcr-p3hp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-25574"},{"type":"PACKAGE","url":"https://github.com/jupyterhub/ltiauthenticator"},{"type":"WEB","url":"https://github.com/jupyterhub/ltiauthenticator/blob/3feec2e81b9d3b0ad6b58ab4226af640833039f3/ltiauthenticator/lti13/validator.py#L122-L164"},{"type":"WEB","url":"https://github.com/jupyterhub/ltiauthenticator/blob/main/CHANGELOG.md#140---2023-03-01"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/jupyterhub-ltiauthenticator/PYSEC-2025-120.yaml"}],"affected":[{"package":{"name":"jupyterhub-ltiauthenticator","ecosystem":"PyPI","purl":"pkg:pypi/jupyterhub-ltiauthenticator"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.3.0"},{"fixed":"1.4.0"}]}],"versions":["1.3.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/02/GHSA-mcgx-2gcr-p3hp/GHSA-mcgx-2gcr-p3hp.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"}]}