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: 2025-04-02 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-29991 is rated Low Risk (19.9/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.13%). Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-29991

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-12 0.01% 0.13% +0.11%
2 2025-04-03 — 0.01% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-29991

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.2 3.1 LOW
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 0.8 1.4 [email protected]

Weakness enumeration for CVE-2025-29991

Affected software / configurations for CVE-2025-29991

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-29991

cvelogic Threat Intelligence