{"id":"CVE-2026-28490","aliases":["GHSA-7432-952r-cw78","PYSEC-2026-2116"],"url":"https://o3.security/vulnerability/CVE-2026-28490","summary":"Authlib Vulnerable to JWE RSA1_5 Bleichenbacher Padding Oracle","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.","published":"2026-03-16T17:37:57.425Z","modified":"2026-07-15T01:49:19.204026291Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"authlib","fixedVersion":"1.6.9"}],"fix":{"url":"https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22","label":"authlib/authlib@48b345f"},"references":[{"type":"WEB","url":"https://github.com/authlib/authlib/releases/tag/v1.6.9"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/28xxx/CVE-2026-28490.json"},{"type":"ADVISORY","url":"https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-28490"},{"type":"FIX","url":"https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-15T01:49:19.204026291Z"}}