Yubico webauthn-server-core (aka java-webauthn-server) 2.8.0 before 2.8.2 incorrectly checks a function's return value in the second factor flow, leading to impersonation.
Exploitability
AV:NAC:HPR:LUI:NScope
S:UImpact
C:HI:HA:H7.5/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HOther