zero-day

adjective

ze·ro-day ˈzir-(ˌ)ō-ˈdā

ˈzē-(ˌ)rō-

computing

: of, relating to, or being a vulnerability (as in a computer or computer system) that is discovered and exploited (as by cybercriminals) before it is known to or addressed by the maker or vendor

Thus, in the parlance of the trade, these vulnerabilities are known as "zero-day exploits," because it has been zero days since they have been uncovered and fixed.—

James Bamford

There's a zero-day vulnerability in RealPlayer and Internet Explorer that allows malicious code to be installed …—

Mark Hopkins

… most of what's on the black market doesn't have that zero-day freshness. Criminals typically target older vulnerabilities, for which fixes have already been released …—

Lev Grossman

Examples of zero-day in a Sentence

Recent Examples on the Web

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

These elite hackers and security researchers work relentlessly to uncover zero-day vulnerabilities in Google’s products and beyond. —

Davey Winder, Forbes, 5 Nov. 2024 The campaign was surprisingly well resourced, exploiting multiple zero-day vulnerabilities the hackers appeared to have discovered in Sophos appliances. —

Andy Greenberg, WIRED, 31 Oct. 2024 Since zero-day attacks are unpredictable, organizations and vendors rely on Zero Trust defenses to mitigate risks. —

Brian Gatke, Forbes, 28 Oct. 2024 Microsoft’s monthly Patch Tuesday security update might have been and gone, but Exploit Wednesday could linger for those users who have not been quick enough to protect their systems against a bunch of zero-day vulnerabilities. —

Davey Winder, Forbes, 12 Oct. 2024 See all Example Sentences for zero-day