Improper Input Validation vulnerabilities
CWE-20 · 12 tracked
Improper input validation (CWE-20) is a broad flaw where an application does not correctly validate input before using it, enabling a wide range of downstream attacks.
How it’s exploited
Because the input isn’t constrained to what the app expects, it can drive injection, buffer issues, logic bypasses, or denial of service depending on where the unvalidated value is used.
How to prevent it
Validate all input against strict allowlists (type, length, format, range) at the trust boundary, and combine with output encoding and safe APIs at each sink.
Tracked improper input validation vulnerabilities
12 CVEs in this class, each with severity, exploit status, EPSS, and remediation.
CVE-2026-55072CVE-2026-47132CVE-2026-71318CVE-2026-70603CVE-2026-70607CVE-2026-70589CVE-2026-54272CVE-2026-69185CVE-2026-69198CVE-2026-59881CVE-2026-69192CVE-2026-54909
Frequently asked questions
- What is Improper Input Validation?
- Improper input validation (CWE-20) is a broad flaw where an application does not correctly validate input before using it, enabling a wide range of downstream attacks.
- How is improper input validation exploited?
- Because the input isn’t constrained to what the app expects, it can drive injection, buffer issues, logic bypasses, or denial of service depending on where the unvalidated value is used.
- How do you prevent improper input validation?
- Validate all input against strict allowlists (type, length, format, range) at the trust boundary, and combine with output encoding and safe APIs at each sink.
- How many improper input validation vulnerabilities are there?
- O3 tracks 12 vulnerabilities classified as CWE-20 (Improper Input Validation), each with severity, exploit status, EPSS exploitation probability, and remediation. The full list is below.