CVE-2025-66406 | Improper Authorization Check for SSH Certificate Revocation

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.

Published: 2025-12-03 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-66406 is rated Low Risk (21.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-66406

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-04 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-66406

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 0.7 4.2 [email protected]

Weakness enumeration for CVE-2025-66406

GitHub Security Advisory for CVE-2025-66406

GHSA-j7c9-79x7-8hpr · Severity: medium · Ecosystem: go — step-ca Has Improper Authorization Check for SSH Certificate Revocation

OS Trackers for CVE-2025-66406

vendor priority summary link
alpine medium CVE-2025-66406: 1 source package rows (step-certificates); 3 state rows across 3 repos (3.22-community, 3.23-community, edge-community); fixed 3, open 0. https://security.alpinelinux.org/vuln/CVE-2025-66406
redhat medium — https://access.redhat.com/security/cve/CVE-2025-66406

Affected software / configurations for CVE-2025-66406

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-66406

cvelogic Threat Intelligence