
Vulnerability management is the continuous process of identifying security weaknesses in an organization’s devices, software and services, deciding which ones matter most, and fixing or mitigating them. It is a cycle, not a one-time scan.
Most organizations cannot fix everything at once. A good process agrees in advance how fast different classes of issue must be handled.
Exploitation happens in the open market. Working exploits, scanning lists of vulnerable hosts and access to unpatched systems are discussed and sold on criminal forums. Signals that a flaw is being actively used, such as an entry in the KEV catalog or chatter about a specific product, should move it to the top of the patch list, especially on internet-facing systems.
Sources: NCSC: Vulnerability management guidance, NIST CSRC Glossary: vulnerability management