39 Methods Documented to Compromise Passkey Authentication Without Breaking FIDO2 Cryptography

Researchers have documented 39 methods for compromising passkey authentication, according to a report published by BleepingComputer on September 4, 2026. The findings, attributed to Token, detail attack vectors that target trust boundaries, authentication prompts, synced credentials, enrollment flows, and recovery mechanisms across FIDO2-based implementations.

The reported methods do not involve breaking the underlying FIDO2 cryptographic protocols. Instead, they abuse operational trust boundaries and user interaction flows to compromise authentication. Specific vectors include manipulation of authentication prompts, exploitation of credential synchronization processes across devices, abuse of enrollment flows, and manipulation of recovery mechanisms.

The report emphasizes that these attacks undermine user confidence in passkey security by demonstrating that compromise can occur without mathematical breaks to the cryptography itself. The findings highlight the importance of securing the broader authentication ecosystem, including user education and platform-level hardening of enrollment and recovery processes.

No public exploit code detailing replication of these methods was included in the reporting. Vendors and platform providers have been urged to review trust boundary designs and strengthen flows that are susceptible to abuse.