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CVE-2026-28490

Authlib Vulnerable to JWE RSA1_5 Bleichenbacher Padding Oracle

Published: Mar 16, 2026Updated: Mar 17, 2026 Sources: CVE List NVD GHSA BDUCWE-203
6.5MEDIUM
NVD MITRE
EPSS Score
0.1%
Top 96.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:NS:UC:HI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-203CWE-327

Affected Products

Red Hat Inc.
commercial·USaka red hat
Red Hat QuayOn-prem
Operating Systems / linux-distro
Red Hat SatelliteOn-prem
Operating Systems / linux-distro
Ansible Automation PlatformOn-prem
Operating Systems / linux-distro
Lightspeed CoreOn-prem
Operating Systems / linux-distro
Red Hat OpenShift AIOn-prem
Operating Systems / linux-distro
Сообщество свободного программного обеспечения
oss-projectaka fsf
Debian GNU/LinuxOn-premOS
Operating Systems / linux-distro
AuthlibLibraryLibrary
OSS Libraries / generic-library
ООО «Ред Софт»
commercial·RUaka red soft
РЕД ОСOn-premOS
Operating Systems / linux-distro
authlib
oss-projectaka jose rfc
authlibLibrary
OSS Libraries / generic-library
PyPI
package-ecosystem
authlib
OSS Libraries

Exploitability

Official Patch Available
Workaround Available
Scannable·OpenVAS
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Collection
Discovery
View detailed technique mapping

References

https://github.com/authlib/authlib
github.com
https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22
github.com
https://github.com/authlib/authlib/releases/tag/v1.6.9
github.com
and 9 more references View all →
News mentions
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