CVE-2026-28490

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.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 4.2

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22	Patch
https://github.com/authlib/authlib/releases/tag/v1.6.9	Product Release Notes
https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78	Exploit Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:*

History

17 Mar 2026, 20:45

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 6.5
First Time		Authlib authlib Authlib
References	~~() https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22 -~~	() https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22 - Patch
References	~~() https://github.com/authlib/authlib/releases/tag/v1.6.9 -~~	() https://github.com/authlib/authlib/releases/tag/v1.6.9 - Product, Release Notes
References	~~() https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78 -~~	() https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78 - Exploit, Mitigation, Vendor Advisory
CPE		cpe:2.3:a:authlib:authlib::::::::

16 Mar 2026, 18:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-03-16 18:16

Updated : 2026-03-17 20:45

NVD link : CVE-2026-28490

Mitre link : CVE-2026-28490

CVE.ORG link : CVE-2026-28490

JSON object : View

Products Affected

authlib

authlib

CWE

CWE-203

Observable Discrepancy

CWE-327

Use of a Broken or Risky Cryptographic Algorithm

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