Bug 2560043

Summary: CVE-2026-114615 python-authlib: Authlib: Authentication bypass via improper asymmetric key validation [epel-9]
Product: [Fedora] Fedora EPEL Reporter: Ronit Dey <rdey>
Component: python-authlibAssignee: Kai A. Hiller <fedora>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: epel9CC: davidkirwanirl, epel-packagers-sig, fedora, python-packagers-sig
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["efa07412-0f98-4213-b90a-2b8a438f4abf"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2559394    

Description Ronit Dey 2026-10-23 17:09:04 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Authlib is a Python library which builds OAuth and OpenID Connect servers. From 1.3.1 until 1.9.0, OctKey.import_key() checks asymmetric-key markers only at byte zero while Authlib's PEM loaders accept leading whitespace, comments, or a byte-order mark. In deployments that use the documented mixed algorithm registry and already configure verification with PEM or certificate bytes containing such a prefix, an unauthenticated attacker who knows those same public-key bytes can use them as an HMAC secret and forge HS256 tokens with arbitrary identity or authorization claims. This is a bypass of the remediation for CVE-2024-37568. The module-level jwt object reaches OctKey.import_key() in authlib/jose/rfc7518/oct_key.py, where POSSIBLE_UNSAFE_KEYS fails to identify prefixed asymmetric key material. This issue is fixed in version 1.9.0.