Bug 2560034

Summary: CVE-2026-114616 python-authlib: authlib: Authentication bypass via zero-length HMAC key [fedora-43]
Product: [Fedora] Fedora Reporter: Ronit Dey <rdey>
Component: python-authlibAssignee: Kai A. Hiller <fedora>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: 43CC: davidkirwanirl, epel-packagers-sig, fedora, python-packagers-sig
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["0ad122df-eddc-44c2-8ea3-d082824403a2"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2559395    

Description Ronit Dey 2026-10-23 16:56:45 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. Prior to 1.9.1, Authlib's OctKey.import_key() and HMAC signing and verification path accept zero-length key material. If an application's secret lookup can return an empty string or empty bytes, a remote attacker can compute the deterministic HS256, HS384, or HS512 signature for arbitrary token claims and have Authlib treat the token as authentic. This issue is fixed in version 1.9.1.