CVE-2025-44005 is a critical-severity (CVSS 10) Improper Authentication vulnerability in github.com/smallstep/certificates. A fix is available for github.com/smallstep/certificates — see the affected versions and patch details below.
Step CA Has Authorization Bypass in ACME and SCEP Provisioners
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2025-44005 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/smallstep/certificatesReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A security fix is now available for Step CA that resolves a vulnerability affecting deployments configured with ACME and/or SCEP provisioners.
All operators running these provisioners should upgrade to the latest release (v0.29.0) immediately.
The issue was discovered and disclosed by a research team during a security review. There is no evidence of active exploitation.
To limit exploitation risk during a coordinated disclosure window, we are withholding detailed technical information for now. A full write-up will be published in several weeks.
Embargo List
If your organization runs Step CA in production and would like advance, embargoed notification of future security updates, visit https://u.step.sm/disclosure to request inclusion on our embargo list.
Acknowledgements
This issue was identified and reported by Stephen Kubik of the Cisco Advanced Security Initiatives Group (ASIG)
Stay safe, and thank you for helping us keep the ecosystem secure.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/smallstep/certificates | all versions | 0.29.0go get github.com/smallstep/certificates@v0.29.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/smallstep/certificates, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/smallstep/certificates to 0.29.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-44005 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-44005 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-44005. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-44005 in your dependencies?
O3 Security finds CVE-2025-44005 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.