CVE-2026-28490
Authlib Vulnerable to JWE RSA1_5 Bleichenbacher Padding Oracle
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-203 CWE-327 |
| Vendor | authlib |
| Product | authlib |
| Published | Mar 16, 2026 |
| Last Updated | Mar 16, 2026 |
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Affected Versions
authlib / authlib
< 1.6.9