kin-openapi: ValidationHandler.Load() Fail-Open Authentication Bypass via NoopAuthenticationFunc Default (getkin kin-openapi)

CVE-2026-73501
CRITICAL 9.1

At a glance

Source
NVD
EPSS
EPSS 0.43 % Β· percentile 37 ()
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Deferred

Description

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.

Weaknesses (CWE)

  • CWE-287 β€” Improper Authentication

References

Scores

VersionScoreVectorScored by
CVSS 3.1CRITICAL 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NGitHub_M
CVSS 3.1CRITICAL 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NNVD Β· security-advisories@github.com (Secondary)

Advisories

European references

Affected products

ProductVersions
getkin Β· kin-openapiaffected < 0.144.0

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST β€” attribution requested
ENISA EUVDENISA β€” reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain β€” this product uses data from the NVD API but is not endorsed or certified by the NVD