EN 40000 Explained: The Technical Blueprint Behind the EU Cyber Resilience Act
The EU Cyber Resilience Act (CRA) is the law, the legal rulebook of what products need to be (from a cybersecurity perspective) in order to be sold within the European Union. The EN 40000 series is the technical guide, the blueprint on how to assess whether your product is compliant with the law. Think of the CRA as the law stating "you must build a safe house," while EN 40000 is the official blueprint showing you exactly how to build it.
The CRA specifies what outcomes manufacturers must achieve—such as "secure configurations" and "protection from unauthorized access"—its legal wording is deliberately high-level and technology-neutral.
How do software developers and hardware manufacturers translate these broad legal mandates into testable, auditable engineering processes? By using the EN 40000 standard series.
What is the EN 40000 Series?
Developed by the European Standardization Organizations CEN and CENELEC via the European Commission’s standardization request, the EN 40000 series serves as the horizontal technical backbone for the CRA.
Harmonised standards are the technical specifications that turn the Cyber Resilience Act's broad Annex I requirements into concrete, testable provisions. "Horizontal" means these standards are generic and cross-industry. Regardless of whether you build smart home thermostats, industrial routers, or industrial machinery, the EN 40000 series establishes the baseline framework that applies to all "products with digital elements."
Instead of forcing companies to rewrite their entire development lifecycles, EN 40000 is designed to be process-agnostic. It seamlessly integrates into existing modern workflows, whether your team utilizes Agile, DevOps, or traditional Waterfall.
Breaking Down the Core Pillars of EN 40000
The standard leverages a highly structured approach, dividing compliance into a modular architecture. The initial layout centers around several key documents:
1. EN 40000-1-1: Vocabulary
Before uniformity can be achieved across the EU, everyone needs to speak the same language. This part establishes clear, legally aligned definitions for core terminology like acceptable risk, residual cybersecurity risk, remote data processing solutions (RDPS), and remediation advisory.
2. EN 40000-1-2: Principles for Cyber Resilience
Spanning over 60 pages, this is the most extensive piece of the horizontal framework. It bridges the gap between high-level risk and concrete engineering. It mandates an explicit structure across the entire product lifecycle based on an Input -> Requirement -> Output -> Assessment workflow. Crucially, it dictates how manufacturers must evaluate third-party open-source components and supply chain risks.
3. EN 40000-1-3: Vulnerability Handling Requirements
No device is perfectly unhackable, which is why the CRA places an immense focus on post-market maintenance. This standard addresses the CRA's Annex I Part II obligations. It lays requirements covering various phases of vulnerability handling—from initial discovery/receipt to public coordinated disclosure and patch deployment.
4. EN 40000-1-4: Product Security Requirements
This section provides the detailed technical requirements for product’s security, according to CRA Annex I. These requirements are the concrete product requirements which need to be met, and which are tested and possibly audited depending on the product category.
The Golden Ticket: Presumption of Conformity
Why should manufacturers care about the EN 40000? Under the CRA, products are categorized into tiers: Default, Important (Class I & II), and Critical.
For Default (Common) products, manufacturers can use the EN 40000 framework to perform a confident self-assessment. Approximately 90% of the connected products fall into this category.
For Important Class I products, a manufacturer successfully applying a finalized, harmonized standard allows the manufacturer to self-assess via internal controls, completely bypassing the time and expense of hiring a third-party Notified Body.
While the EN 40000 series will be the overarching, horizontal framework for the CRA, it is not the only one. To make the CRA realistic across hundreds of different types of technology, dozens of other standards will be harmonized to grant a presumption of conformity (for example global standards like IEC 62443).
Test of Things and EN 40000-1-X
We at Test of Things are contributing to the EN 40000 standardisation work as part of the working group.
Many customers have already expressed their strong interest in EN 40000 -standard as part of their CRA compliance work. We will be supporting EN 40000 compliance management and testing as the first provider immediately upon the finalization of the standard (among our other supported product standards like IEC 62443-4-2).
Follow us for all updates on standards development and products’ cybersecurity compliance management.
