Base weakness
Draft
CWE-440: Expected Behavior Violation
A feature, API, or function does not perform according to its specification.
Last updated
34
Recorded CVEs
With this primary weakness
0
KEVs
In the CISA KEV catalog
Not rated
Likelihood of exploit
Per MITRE
Base
Abstraction
MITRE classification
Overview
CWE-440 (Expected Behavior Violation) is a base-level software weakness catalogued by MITRE in the Common Weakness Enumeration (CWE). It describes a recurring type of mistake that can lead to exploitable security vulnerabilities.
Real-world CVEs
34 recorded CVEs are caused by CWE-440 (Expected Behavior Violation). The highest-severity and most recent are shown first. 3 new CWE-440 CVEs have been recorded so far in 2026 (12 in 2025).