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TI-2026-29598 Aliases CVE-2026-40947GHSA-6vgr-gf7r-f3jc

Untrusted search path in Yubico libfido2

Priority LOW 13CWE-426Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Code execution
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-426.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00131 2nd percentileScored 2026-11-07
Fix Fixed libfido2 (Yubico): 1.17.0python-fido2 (Yubico): 2.2.0+1 more product

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Yubicolibfido2before 1.17.01.17.0Patch availableCNA
Yubicopython-fido2before 2.2.02.2.0Patch availableCNA
Yubicoyubikey-managerbefore 5.9.15.9.1Patch availableCNA
  • libfido2 VendorYubico Affected before 1.17.0 Fixed in 1.17.0 Patch available CNA
  • python-fido2 VendorYubico Affected before 2.2.0 Fixed in 2.2.0 Patch available CNA
  • yubikey-manager VendorYubico Affected before 5.9.1 Fixed in 5.9.1 Patch available CNA

Remediation

  • Fix · CNA libfido2 (Yubico) Fixed in 1.17.0
  • Fix · CNA python-fido2 (Yubico) Fixed in 2.2.0
  • Fix · CNA yubikey-manager (Yubico) Fixed in 5.9.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-40947
  2. 2026-10-03 Alias added: GHSA-6vgr-gf7r-f3jc

References

Other 1

  • TI-2023-20808 The PKCS11 module of the YubiHSM 2 SDK through 2023.01 does not properly validate the… CVSS 3.1HIGH 7.5
  • TI-2011-03638 Improper input validation in yubico-pam CVSS 3.1CRITICAL 9.8
  • TI-2020-08207 The sync endpoint in YubiKey Validation Server before 2.40 allows remote attackers to… CVSS 3.1HIGH 8.6
  • TI-2019-09116 In Yubico pam-u2f 1.0.7, when configured with debug and a custom debug log file is set… CVSS 3.0HIGH 8.1
  • TI-2018-06723 In check_user_token in util.c in the Yubico PAM module (aka pam_yubico) 2.18 through… CVSS 3.0HIGH 8.2
  • TI-2015-02918 Yubico ykneo-openpgp before 1.0.10 has a typo in which an invalid PIN can be used. CVSS 3.1HIGH 8.8
See all 29 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences