HighFix available
python-authlib — security advisory
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.
- Products
- python-authlib
- Affected versions
- 0.15.4-1, 0.15.5-1, 0.15.5-1ubuntu0.1~esm1, 1.2.1-1, 1.3.0-1, 1.3.0-1ubuntu0.1~esm1, 1.5.1-1, 1.5.2-1, 1.6.0-1, 1.6.5-1, 1.6.6-1, 1.6.7-1, 1.7.2-1, 1.7.2-2
- Fixed versions
- 0.15.5-1ubuntu0.1~esm2, 1.3.0-1ubuntu0.1~esm2, 1.6.7-1ubuntu0.1~esm1
- CVEs
- CVE-2026-28490
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:06 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2026-28490
python-authlib
Fixed versions: 0.15.5-1ubuntu0.1~esm2
python-authlib
Fixed versions: 1.3.0-1ubuntu0.1~esm2
python-authlib
Fixed versions: Not specified
python-authlib
Fixed versions: Not specified
python-authlib
Fixed versions: 1.6.7-1ubuntu0.1~esm1
Complete source record
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"modified": "2026-10-17T12:58:08.502442569Z",
"provider": "osv",
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"references": [
"https://ubuntu.com/security/CVE-2026-28490",
"https://www.cve.org/CVERecord?id=CVE-2026-28490",
"https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78",
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"source_id": "core-osv",
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"published_at": "2026-03-16T18:16:00+00:00"
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