CVE-2026-40947: Yubico libfido2 · Untrusted Search Path
Affects Yubico libfido2Source CVE Database V5
Not known to be exploited · CVSS 2.9 Low : upgrade to 1.17.0 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.17.0, 2.2.0, 5.9.1
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 15 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade libfido2 to 1.17.0; python-fido2 to 2.2.0; yubikey-manager to 5.9.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Yubicolibfido2 | Affected
| Fixed in
|
| Yubicopython-fido2 | Affected
| Fixed in
|
| Yubicoyubikey-manager | Affected
| Fixed in
|
PyPIpython-fido2pkg:pypi/python-fido2Other threats | Affected
| Fixed in
|
PyPIyubikey-managerpkg:pypi/yubikey-managerOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, restrict local access to trusted users and environments to reduce risk. Monitor for vendor updates regarding patches or official mitigations.
Description
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.