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 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.

Score

CVSS 3.1 9.1 Critical

Status

Deferred - security-advisories@github.com

Published

2026-08-12

Last modified

2026-10-24

Weaknesses

CWE-287

Affected products

• Kin-openapi (Getkin)

References

• https://github.com/getkin/kin-openapi/security/advisories/GHSA-r277-6w6q-xmqw
• https://github.com/getkin/kin-openapi/commit/f0407d53b0730280266f454b755010e7eeb985da
• https://github.com/getkin/kin-openapi/releases/tag/v0.144.0