Methodology

Every figure here comes from a named primary source on a fixed schedule. This page explains exactly how, so you can check our work rather than take it on trust.

Where the data comes from

We use primary sources only — the organisation that publishes the fact, not an aggregator that republishes it. Today that means:

How often we check

The KEV catalog is refetched twice a day and the NVD feed once a day. Each page shows its own last verified timestamp and its next scheduled check. Those are not decorative — they are written by the job that did the fetching.

What happens when a fetch fails

This is the part most sites get wrong, so it is worth stating plainly.

When a source is unreachable, we keep the previous data and its original verified date. We do not restamp it. The page visibly goes stale rather than showing old data behind a fresh-looking timestamp.

  • Past its freshness budget, a page's status indicator turns amber.
  • Past twice that budget, the page carries a visible banner telling you so.
  • Three consecutive failures raise an alert to a human.

The fetcher also refuses any response that shrinks the catalog by more than 10%, because that means a truncated or malformed payload rather than a real change.

Facts live in exactly one place

If a number appears on several pages, all of them read it from the same file. The entry count on the homepage, the tracker index and the tracker page are the same variable, not three copies that can drift apart.

What is automated and what is not

Data is written by scheduled jobs. Judgement is not. A confidence rating — confirmed, expected, rumoured or disputed — is set by a person, and no automated job is permitted to overwrite it.

Descriptions on CVE pages are CISA's own words, attributed as such. Where we add interpretation, we say so.

Corrections

If something here is wrong, tell us and we will check it against the source. Every data page has a Report an error link. Corrections to a tracked fact are recorded in that page's change log rather than quietly edited.

What we do not do

  • We do not accept payment for placement in any ranking.
  • We do not publish a date or a figure without a source link.
  • We do not present a vendor's claim as an independent finding.
  • Tools run in your browser. We do not collect what you type into them.

Last updated July 30, 2026 · CyTools