A 0-Day is a software vulnerability without an available fix, creating risk because defenders have limited time to mitigate exploitation.
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Background for this topic.
0-Day describes a software vulnerability unknown to the software maker or unpatched when first exploited. Attackers can use these flaws immediately, as no official fix or signature exists to block the exploit. Such vulnerabilities often affect widely deployed software or hardware, making them valuable for targeted attacks or widespread campaigns.
Because defenders lack patches or reliable detection signatures initially, they must rely on anomaly detection, network monitoring, and threat intelligence to identify suspicious activity linked to 0-day exploits. Rapid patching once a fix is released is critical to reduce exposure. Tracking emerging 0-day threats helps prioritize defensive measures and informs risk management decisions in environments where unpatched vulnerabilities pose significant security risks.
Ivanti has released security updates to patch a critical Connect Secure remote code execution vulnerability exploited by a China-linked espionage actor to deploy malware since at least mid-March 2025. [...]
Espionage? Botnets? Trying to exploit a zero-day? Someone or something is probing devices made by Juniper Networks and Palo Alto Networks, and researchers think it could be evidence of espionage attempts, attempts to build a botnet, or an effort to exploit zero-day vulnerabilities.…
Apple has released security updates that backport fixes for actively exploited vulnerabilities that were exploited as zero-days to older versions of its operating systems. [...]
The threat actors behind the zero-day exploitation of a recently-patched security vulnerability in Microsoft Windows have been found to deliver two new backdoors called SilentPrism and DarkWisp
Every week, someone somewhere slips up—and threat actors slip in. A misconfigured setting, an overlooked vulnerability, or a too-convenient cloud tool becomes the perfect entry point. But what happens when the hunters become the hunted? Or when old malware resurfaces with new tricks? Step behind the curtain with us this week as we explore breaches born from routine oversights—and the unexpected