Yubico YubiKey 5.4.1 through 5.7.3 before 5.7.4 has an incorrect FIDO CTAP PIN/UV Auth Protocol Two implementation. It uses the signature length from CTAP PIN/UV Auth Protocol One, even when CTAP PIN/UV Auth Protocol Two was chosen, resulting in a partial signature verification.
CVE ID: CVE-2025-29991
CVSS Base Severity: LOW
CVSS Base Score: 2.2
CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N
Vendor: Yubico
Product: YubiKey
EPSS Score: 0.01% (probability of being exploited)
EPSS Percentile: 1.04% (scored less or equal to compared to others)
EPSS Date: 2025-04-18 (when was this score calculated)