Bug 2460004 (CVE-2026-6856)

Summary: CVE-2026-6856 keycloak: keycloak: acceptable AAGUID policy bypass via packed self-attestation in WebAuthn registration
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: aschwart, asoldano, aszczucz, bbaranow, bmaxwell, boliveir, bstansbe, dlofthou, drichtar, istudens, ivassile, iweiss, mosmerov, mposolda, msvehla, nwallace, pberan, pesilva, pjindal, pmackay, rmartinc, rstancel, smaestri, ssilvert, sthorger, thjenkin, vdosoudi, vmuzikar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2026-04-21 08:08:29 UTC
WebAuthn AAGUID policy bypass via packed self-attestation. Similar to CVE-2025-12150. When direct attestation is requested but the authenticator sends self-attestation (no x5c), the AAGUID is unverified, allowing bypass of the acceptable AAGUID allowlist.

Affects RHBK 26.4 and Keycloak 26.6. Patch in progress.