{"id":"PYSEC-2026-2116","details":"Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a cryptographic padding oracle vulnerability was identified in the Authlib Python library concerning the implementation of the JSON Web Encryption (JWE) RSA1_5 key management algorithm. Authlib registers RSA1_5 in its default algorithm registry without requiring explicit opt-in, and actively destroys the constant-time Bleichenbacher mitigation that the underlying cryptography library implements correctly. This issue has been patched in version 1.6.9.","aliases":["CVE-2026-28490","GHSA-7432-952r-cw78"],"modified":"2026-07-13T07:15:14.229863781Z","published":"2026-03-16T18:16:07.557Z","references":[{"type":"ADVISORY","url":"https://github.com/authlib/authlib/releases/tag/v1.6.9"},{"type":"FIX","url":"https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22"},{"type":"EVIDENCE","url":"https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78"}],"affected":[{"package":{"name":"authlib","ecosystem":"PyPI","purl":"pkg:pypi/authlib"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.9"}]}],"versions":["0.1","0.10","0.11","0.12","0.12.1","0.13","0.14","0.14.1","0.14.2","0.14.3","0.15","0.15.1","0.15.2","0.15.3","0.15.4","0.15.5","0.15.6","0.1rc0","0.2","0.2.1","0.3","0.4","0.4.1","0.5","0.5.1","0.6","0.7","0.8","0.9","1.0.0","1.0.0a1","1.0.0a2","1.0.0b1","1.0.0b2","1.0.0rc1","1.0.1","1.1.0","1.2.0","1.2.1","1.3.0","1.3.1","1.3.2","1.4.0","1.4.1","1.5.0","1.5.1","1.5.2","1.6.0","1.6.1","1.6.2","1.6.3","1.6.4","1.6.5","1.6.6","1.6.7","1.6.8"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/authlib/PYSEC-2026-2116.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N"}]}