CVE-2026-30836Network attack vector

Unauthenticated certificate issuance via unsupported SCEP message

Published Mar 19, 2026 · Updated Mar 19, 2026

Improper authentication in Smallstep step-ca before 0.30.0 allows remote attackers to obtain certificates through SCEP UpdateReq messages. PKIOperation accepted the valid but unsupported MessageType 18, parsed its CSR, and continued without the SCEP challenge authorization enforced for supported requests. A reachable SCEP provisioner is required; authorization webhooks and CA name and validity policies still constrain the issued certificate.

CVSS severity10.0
Critical
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Smallstep step-ca before 0.30.0 allows remote attackers to obtain certificates through SCEP UpdateReq messages. PKIOperation accepted the valid but unsupported MessageType 18, parsed its CSR, and continued without the SCEP challenge authorization enforced for supported requests. A reachable SCEP provisioner is required; authorization webhooks and CA name and validity policies still constrain the issued certificate.

The record

CVE
CVE-2026-30836
Published
Mar 19, 2026
Updated
Mar 19, 2026
Vendor
Smallstep
Product
step-ca
Classifications
CWE-295, CWE-287, T1649
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.30.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Smallstep · step-caversion=< 0.30.0

Published CVSS scores

10.0GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-295Improper Certificate Validation
CWE-287Improper Authentication
T1649Steal or Forge Authentication Certificates

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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