Zero-day vulnerability

<p>A zero-day (also known as a 0-day) is a <a href="/facts/Vulnerability_(computer_security)/jg0Gr71M">vulnerability</a> or security hole in a <a href="/facts/Computer/SQe1aK05">computer</a> system unknown to its developers or anyone capable of <a href="/facts/Mitigation/VjCAqP3F">mitigating</a> it. Until the vulnerability is remedied, <a href="/facts/Threat_actor/7MMDYfDb">threat actors</a> can <a href="/facts/Exploit_(computer_security)/EdlqsRJM">exploit</a> it in a zero-day exploit, or zero-day attack.
</p><p>The term "zero-day" originally referred to the number of days since a new piece of <a href="/facts/Software/RP79lVSW">software</a> was released to the public, so "zero-day software" was obtained by hacking into a developer's computer before release. Eventually the term was applied to the vulnerabilities that allowed this hacking, and to the number of days that the vendor has had to fix them. Vendors who discover the vulnerability may create <a href="/facts/Patch_(computing)/sIHVBPls">patches</a> or advise <a href="/facts/Workaround/UF6B69P4">workarounds</a> to mitigate it – though users need to deploy that mitigation to eliminate the vulnerability in their systems. Zero-day attacks are severe <a href="/facts/Threat_(computer_security)/5RHTbSac">threats</a>.
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Zero-day vulnerability open-in-new

Zero-day vulnerability