smallstep certificates up to 0.28.x SSH Certificate authorization

Summaryinfo

A vulnerability has been found in smallstep certificates up to 0.28.x and classified as problematic. The affected element is an unknown function of the component SSH Certificate Handler. Performing a manipulation results in authorization. This vulnerability is reported as CVE-2025-66406. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic has been found in smallstep certificates up to 0.28.x. This affects an unknown part of the component SSH Certificate Handler. The manipulation with an unknown input leads to a authorization vulnerability. CWE is classifying the issue as CWE-863. The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions. This is going to have an impact on integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2025-66406 since 11/29/2025. The exploitability is told to be difficult. It is possible to initiate the attack remotely. Additional levels of successful authentication are required for exploitation. Neither technical details nor an exploit are publicly available.

Upgrading to version 0.29.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-201014). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• smallstep

Name

• certificates

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28

Website

• Product: https://github.com/smallstep/certificates/

CPE 2.3info

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CPE 2.2info

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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