CVE-2026-73501
kin-openapi is a Go project for handling OpenAPI files. Prior to 0.144.0, ValidationHandler.Load() in openapi3filter/validation_handler.go s
CVSS
9.1
Critical
EPSS
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KEV
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Exploit Today
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0-100
Published: Aug 12, 2026 · Last modified: Aug 12, 2026 · CWE-287
Not enough EPSS history yet.
kin-openapi is a Go project for handling OpenAPI files. Prior to 0.144.0, ValidationHandler.Load() in openapi3filter/validation_handler.go silently replaces a nil AuthenticationFunc with NoopAuthenticationFunc, which returns nil without checking credentials. This substitution causes every OpenAPI security requirement to be satisfied for unauthenticated requests when an application relies on ValidationHandler as its enforcement middleware. The no-op callback prevents the fail-closed ErrAuthenticationServiceMissing path from being reached and forwards the request to protected handlers that may require an API key, OAuth token, or another security scheme. This issue is fixed in version 0.144.0.