The sync endpoint in YubiKey Validation Server before 2.40 allows remote attackers to…
Priority MEDIUM 41CWE-294Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · Low · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-294.
Summary
The sync endpoint in YubiKey Validation Server before 2.40 allows remote attackers to replay an OTP. NOTE: this issue is potentially relevant to persons outside Yubico who operate a self-hosted OTP validation service with a non-default configuration such as an open sync pool; the issue does NOT affect YubiCloud.
Why it matters now
EPSS 0.01682 77th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2020-10185
- 2026-10-03 Alias added: GHSA-xcc3-mxq7-rg5h
References
More Yubico Yubikey One Time Password Validation Server vulnerabilities
- TI-2020-08206 The verify endpoint in YubiKey Validation Server before 2.40 does not check the length of… CVSS 3.1HIGH 7.5
Sources
- CVE-2020-10185 · CVE Program
- CVE-2020-10185 · NVD
- FIRST EPSS
- GHSA-xcc3-mxq7-rg5h · GitHub Advisory Database · CC BY 4.0
- CVE-2020-10185 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences