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.
Consider yourselves compromised, experts warn Ivanti has patched two critical zero-day vulnerabilities in its Endpoint Manager Mobile (EPMM) product that are already being exploited, continuing a grim run of January security incidents for enterprise IT vendors.…
Ivanti has rolled out security updates to address two security flaws impacting Ivanti Endpoint Manager Mobile (EPMM) that have been exploited in zero-day attacks, one of which has been added by the U.S. Cybersecurity and Infrastructure Security Agency (CISA) to its Known Exploited Vulnerabilities (KEV) catalog
Ivanti has disclosed two critical vulnerabilities in Ivanti Endpoint Manager Mobile (EPMM), tracked as CVE-2026-1281 and CVE-2026-1340, that were exploited in zero-day attacks. [...]
To stop the ongoing attacks, the cybersecurity vendor took the drastic step of temporarily disabling FortiCloud single sign-on (SSO) authentication for all devices.
Mitigation: SSO Access Restricted After Attackers Compromised Fully Patched DevicesNetwork security giant Fortinet locked out cloud customers from its single sign-on service until they update device firmware with a patch against active attacks exploiting an improper access control zero day. Only Fortinet devices running the latest, patched firmware versions can use Fortinet SSO.
Fortinet has confirmed a new, actively exploited critical FortiCloud single sign-on (SSO) authentication bypass vulnerability, tracked as CVE-2026-24858, and says it has mitigated the zero-day attacks by blocking FortiCloud SSO connections from devices running vulnerable firmware versions. [...]
To exploit the vulnerability, an attacker would need either system access or be able to convince a user to open a malicious Office file.
Another actively abused Office bug, another emergency patch – Office 2016 and 2019 users are left with registry tweaks instead of fixes. Microsoft has issued an emergency Office patch after confirming a zero-day flaw is already being used in real world attacks.…
Microsoft on Monday issued out-of-band security patches for a high-severity Microsoft Office zero-day vulnerability exploited in attacks
Microsoft has released emergency security updates to patch a high-severity Office zero-day vulnerability exploited in attacks. [...]
Also, cybercriminals get breached, Gemini spills the calendar beans, and more infosec in brief T'was a dark few days for automotive software systems last week, as the third annual Pwn2Own Automotive competition uncovered 76 unique zero-day vulnerabilities in targets ranging from Tesla infotainment to EV chargers.…