Glossary · Devices and software

Firmware

Updated 22 September 20261 min read
Short answer

Firmware is the software built into a piece of hardware, such as a router or firewall, that makes the hardware work. For Cyber Essentials, router and firewall firmware counts as an operating system: it must be supported by the vendor (A6.1) and its critical and high-risk updates installed within 14 days (A6.4, an automatic fail if answered No).

Key facts
Term
Also known as
Requirement area
Reviewed against

What does the term firmware mean in Cyber Essentials?

Firmware is the software built into a piece of hardware, such as a router or firewall, that makes the hardware work.

How does firmware apply to Cyber Essentials?

In plain terms

The router your broadband provider sent and the firewall box in the comms cupboard both have software inside them. You rarely see it, and nobody logs into these boxes day to day, so it is easy to forget. That hidden software is firmware. The maker releases updates for it just as Apple does for an iPhone, but someone usually has to apply them.

What Cyber Essentials asks

The NCSC definition of software includes "firewall and router firmware", so it falls under the security update management control. The question set is explicit. A6.1 says "the firmware of these devices is considered to be an operating system and needs to meet this requirement". A6.4 says the 14-day rule "includes the firmware on your firewalls and routers". A6.4.2 asks how you make sure those updates go on within 14 days where automatic updates are not used. A2.5 asks for the make, model and quantity of each router and firewall, which lets the assessor check that the model is still supported.

Common mistakes

  • Running a firewall or router model the maker no longer updates. It has to be replaced, or the requirement is not met.
  • Having no named person or routine for checking firmware releases. Describe the routine in A6.4.2.
  • Listing staff home routers. The A2.5 guidance says details of routers and firewalls in the home environment must not be included.

See the security update management requirements and the DrayTek setup guide. Related: boundary firewall, router, operating system.

Related terms

Frequently asked questions

Firmware is the software built into a piece of hardware, such as a router or firewall, that makes the hardware work.

In the 2026 Danzell question set, firmware comes up at A2.5, A6.1, A6.4, A6.4.2. Read those questions against the definition above so your answers use the term the way the assessor will.

Firmware relates to B. Definitions; 3. Security Update Management in the NCSC's Cyber Essentials: Requirements for IT Infrastructure v3.3. Read that section for the control your answers must show.

Free readiness check

Would you pass the 2026 question set?

Answer 24 yes or no questions, built by the assessors who mark Cyber Essentials, and get a readiness score in about five minutes, with any auto-fail questions you miss flagged first in your results.

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