Zero Day

nouncandidate·updated May 9, 2026

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The "Day Zero" or "Zero Day" is the day a new vulnerability is made known. In some cases, a "zero day" exploit is referred to an exploit for which no patch is available yet. ("day one" - day at which the patch is made available).

MWE

Classifications

per-axis with provenance

Entity Type

Vulnerability95%rule-basedr:entity.vulnerability.cve.v1

?unassignedlast reviewed —

Sensitivity

unclassified

Information Class

unclassified

Variants

3 surface forms

plural: Zero Days
possessive: Zero Day's
pluralpossessive: Zero Days'

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