CVE-2026-40947

Yubico libfido2 before 1.17.0, python-fido2 before 2.2.0, and yubikey-manager before 5.9.1 have an unintended DLL search path.

Published: 2026-04-16 Last update: 2026-04-17 Assigner: [email protected] Source: [email protected]
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-40947 is rated Low Risk (12.2/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.01%). 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-2026-40947

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 2026-04-16 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-40947

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
2.9 3.1 LOW
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/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:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
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.
 1.4 1.4 [email protected]

Weakness enumeration for CVE-2026-40947

OS Trackers for CVE-2026-40947

vendor priority summary link
debian unimportant CVE-2026-40947 unimportant priority: Debian including 3 source packages (libfido2, python-fido2, yubikey-manager), 15 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 15. https://security-tracker.debian.org/tracker/CVE-2026-40947
suse low CVE-2026-40947 severity low: SUSE including 9 source package names (libfido2, libfido2-1, …), 129 product×package rows across 26 product lines (SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS, … (26 product lines)): Known Not Affected 129. https://www.suse.com/security/cve/CVE-2026-40947/
ubuntu medium CVE-2026-40947 medium priority: Ubuntu including 3 source packages (libfido2, python-fido2, yubikey-manager), 15 status rows across 5 suites (focal, jammy, noble, questing, upstream): not-affected 15. https://ubuntu.com/security/CVE-2026-40947

Affected software / configurations for CVE-2026-40947

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-40947

cvelogic Threat Intelligence