Vulnerability in Yubico Yubikey

CVE-2025-29991

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 2.2 (Low). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.001 (1.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 1.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-29991: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-29991?
CVE-2025-29991 is a low-severity vulnerability in Yubico Yubikey, classified under Weak Authentication. CVSS score: 2.2/10. Published 2025-04-03.
How severe is CVE-2025-29991?
Low severity. CVSS v3 base score is 2.2 out of 10.