Data Card
Yubico ships YubiKey firmware 5.8 with hardware-backed signing
Yubico released YubiKey firmware version 5.8, adding CTAP 2.3 support and a preview of the WebAuthn signing extension for hardware-backed approvals.
2026-07-21CC-BY-4.0yubicowebauthnctaphardware-authenticators
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Key Facts
- Firmware 5.8 supports CTAP 2.3 and a preview of the WebAuthn signing extension.
- Hardware-backed signing targets transaction approvals, AI agent authorizations, and payment confirmations.
- Enterprise Attestation supports up to 16 relying-party identifiers.
Card Text
The signing extension extends security keys beyond proving who is present toward attesting what was approved, which matters as autonomous agents begin initiating transactions. Binding an approval to hardware gives relying parties an audit artifact that session-based authentication does not produce.