CVE-2025-66406: GO-2025-4181 - step-ca Has Improper Authorization Check for SSH Certificate Revocation in github.com/smallstep/certificates

CVE-2025-66406 · Severity: medium · CVSS 5 · Published 2025-12-03

Step CA is an online certificate authority for secure, automated certificate management for DevOps. Prior to 0.29.0, there is an improper authorization check for SSH certificate revocation. This affects deployments configured with the SSHPOP provisioner. This vulnerability is fixed in 0.29.0.

Technologies: github.com/smallstep/certificates (Go). Vendors: Go.

Quick answers

Is CVE-2025-66406 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2025-66406 being exploited in the wild.
How severe is CVE-2025-66406?
Medium severity, with a CVSS score of 5, published 3 December 2025.
Which products and versions are affected?
github.com/smallstep/certificates (Go) SEMVER:introduced=0,fixed=0.29.0.
Is there a fix for CVE-2025-66406?
Yes. github.com/smallstep/certificates (Go): upgrade to 0.29.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2025-66406?
Check whether you run github.com/smallstep/certificates (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/smallstep/certificates (Go): upgrade to 0.29.0 or later
    go get github.com/smallstep/certificates@v0.29.0

Affected products

  • github.com/smallstep/certificates (Go) SEMVER:introduced=0,fixed=0.29.0

Identifiers

  • CVE-2025-66406
  • GHSA-j7c9-79x7-8hpr
  • GO-2025-4181

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