FAQ

A CVE is simply a public declaration that a flaw exists in a given product, whereas an exploited vulnerability means that an attacker is actively using that flaw to compromise systems. In other words, not all CVEs are exploited in real-world conditions—some may remain theoretical or technical.

Conversely, a vulnerability can be exploited without yet having received a CVE—this is known as a zero-day. To assess the real danger of a CVE, one should consult additional information such as CISA’s KEV data or the EPSS score, which indicate whether the flaw is actively used in cyberattacks. This information is available directly on our CVEFind website.

A zero-day vulnerability is a security flaw that is not yet known to the public or the software vendor. It is called 'zero-day' because the developers have had zero days to fix it at the time of discovery or exploitation. In other words, no protection or patch exists when the attack occurs.

These vulnerabilities can affect any component: operating systems, software, hardware, firmware, or web services. When identified by malicious actors before defenders, they pose a critical risk as they can be exploited silently and without immediate defense.

Zero-day vulnerabilities are especially dangerous because they are unknown and unpredictable. Since no patch is available yet, vulnerable systems are exposed with no immediate solution. Traditional protections like antivirus or IDS/IPS may not detect the exploitation of a zero-day.

Due to their strategic value, zero-days are often used in targeted and stealthy attacks by organized cybercriminals or state-sponsored actors. They enable attackers to infiltrate systems, remain undetected, and exfiltrate or manipulate sensitive data.

Exploiting a zero-day involves creating a specific exploit, which is code or a method that takes advantage of the flaw before it’s patched. Attackers can deliver it via a malicious document, a compromised website, malware, or a phishing email.

Once triggered, the exploit may take control of the system, install a trojan, open a backdoor, or steal data. What makes zero-day exploits especially dangerous is that they bypass conventional detection tools, leveraging unknown weaknesses.

A CVE (Common Vulnerabilities and Exposures) is a security flaw that has been publicly identified, documented, and published in an official database. It is known and, in most cases, a patch is available or in progress. A zero-day, on the other hand, is a flaw that has not yet been disclosed, and therefore is not listed as a CVE at the time of discovery.

In short, every zero-day can become a CVE, but not all CVEs are zero-days. The main risk with zero-days is that they are exploitable before any public awareness, whereas CVEs are typically already under analysis or remediation.