Cybersecurity

Vulnerability

Definition

In computer security, a vulnerability is a weakness which can be exploited by a threat actor, such as an attacker, to perform unauthorized actions within a computer system.

Why It Matters

Vulnerabilities are the "holes" that attackers look for to break into a system. Managing and patching vulnerabilities is a fundamental part of cybersecurity.

Contextual Example

A piece of software might have a "buffer overflow" vulnerability, where providing a very long input can crash the program or even allow an attacker to execute arbitrary code. The vendor would then release a patch to fix this vulnerability.

Common Misunderstandings

  • A vulnerability is a weakness. An "exploit" is a piece of code that takes advantage of a vulnerability. A "threat" is the potential for an exploit to occur.
  • Vulnerabilities are tracked in public databases using CVE (Common Vulnerabilities and Exposures) identifiers.

Related Terms

Last Updated: December 17, 2025