CVE-2026-30836 | Step CA: Unauthenticated Certificate Issuance via SCEP UpdateReq (MessageType=18)

Step CA is an online certificate authority for secure, automated certificate management for DevOps. Versions 0.30.0-rc6 and below do not safeguard against unauthenticated certificate issuance through the SCEP UpdateReq. This issue has been fixed in version 0.30.0.

Published: 2026-03-19 Last update: 2026-04-27 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-30836 is rated Moderate Risk (40.2/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.01%). Review affected assets and schedule remediation.

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-2026-30836

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 2026-03-20 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-30836

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
10.0 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 5.8 [email protected]

Weakness enumeration for CVE-2026-30836

GitHub Security Advisory for CVE-2026-30836

GHSA-q4r8-xm5f-56gw · Severity: critical · Ecosystem: go — step-ca has Unauthenticated Certificate Issuance via SCEP UpdateReq (MessageType=18)

OS Trackers for CVE-2026-30836

vendor priority summary link
alpine — CVE-2026-30836: 1 source package rows (step-certificates); 2 state rows across 2 repos (3.23-community, edge-community); fixed 2, open 0. https://security.alpinelinux.org/vuln/CVE-2026-30836
redhat critical — https://access.redhat.com/security/cve/CVE-2026-30836
suse critical — https://www.suse.com/security/cve/CVE-2026-30836/
ubuntu medium CVE-2026-30836 medium priority: Ubuntu including 1 source packages (golang-github-smallstep-certificates), 4 status rows across 4 suites (jammy, noble, questing, upstream): needs-triage 3, DNE 1. https://ubuntu.com/security/CVE-2026-30836

Affected software / configurations for CVE-2026-30836

Vendor Product Version Raw CPE
smallstep step-ca < 0.30.0 cpe:2.3:a:smallstep:step-ca:*:*:*:*:*:go:*:*
smallstep step-ca 0.30.0 cpe:2.3:a:smallstep:step-ca:0.30.0:rc1:*:*:*:go:*:*
smallstep step-ca 0.30.0 cpe:2.3:a:smallstep:step-ca:0.30.0:rc2:*:*:*:go:*:*
smallstep step-ca 0.30.0 cpe:2.3:a:smallstep:step-ca:0.30.0:rc3:*:*:*:go:*:*
smallstep step-ca 0.30.0 cpe:2.3:a:smallstep:step-ca:0.30.0:rc4:*:*:*:go:*:*
smallstep step-ca 0.30.0 cpe:2.3:a:smallstep:step-ca:0.30.0:rc5:*:*:*:go:*:*
smallstep step-ca 0.30.0 cpe:2.3:a:smallstep:step-ca:0.30.0:rc6:*:*:*:go:*:*

References for CVE-2026-30836

cvelogic Threat Intelligence