CVE-2026-73501
kin-openapi: ValidationHandler.Load() Fail-Open Authentication Bypass via NoopAuthenticationFunc Default
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.
INFO
Published Date :
Aug. 12, 2026, 10:17 p.m.
Last Modified :
Oct. 24, 2026, 3:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-73501
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 3.1 | CRITICAL | MITRE-CVE |
Solution
- Update kin-openapi to version 0.144.0.
- Verify authentication middleware functions correctly.
- Re-evaluate security requirements implementation.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-73501.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-73501 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-73501
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-73501 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-73501 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 24, 2026
Action Type Old Value New Value Changed Translation Title: kin-openapi de getkin, Description: kin-openapi es un proyecto Go para manejar archivos OpenAPI. Antes de la versión 0.144.0, ValidationHandler.Load() en openapi3filter/validation_handler.go reemplaza silenciosamente una AuthenticationFunc nula con NoopAuthenticationFunc, que devuelve nil sin verificar las credenciales. Esta sustitución hace que cada requisito de seguridad de OpenAPI se satisfaga para solicitudes no autenticadas cuando una aplicación depende de ValidationHandler como su middleware de aplicación. La devolución de llamada no-op impide que se alcance la ruta fail-closed ErrAuthenticationServiceMissing y reenvía la solicitud a manejadores protegidos que pueden requerir una clave API, un token OAuth u otro esquema de seguridad. Este problema se corrige en la versión 0.144.0. Title: kin-openapi de getkin, Description: kin-openapi es un proyecto Go para manejar archivos OpenAPI. Antes de la versión 0.144.0, ValidationHandler.Load() en openapi3filter/validation_handler.go reemplaza silenciosamente una AuthenticationFunc nula con NoopAuthenticationFunc, que devuelve nil sin verificar las credenciales. Esta sustitución hace que cada requisito de seguridad de OpenAPI se satisfaga para solicitudes no autenticadas cuando una aplicación depende de ValidationHandler como su middleware de aplicación. La devolución de llamada no-op impide que se alcance la ruta fail-closed ErrAuthenticationServiceMissing y reenvía la solicitud a manejadores protegidos que pueden requerir una clave API, un token OAuth u otro esquema de seguridad. Este problema se corrige en la versión 0.144.0. -
CVE Translated by [email protected]
Oct. 23, 2026
Action Type Old Value New Value Added Translation Title: kin-openapi de getkin, Description: kin-openapi es un proyecto Go para manejar archivos OpenAPI. Antes de la versión 0.144.0, ValidationHandler.Load() en openapi3filter/validation_handler.go reemplaza silenciosamente una AuthenticationFunc nula con NoopAuthenticationFunc, que devuelve nil sin verificar las credenciales. Esta sustitución hace que cada requisito de seguridad de OpenAPI se satisfaga para solicitudes no autenticadas cuando una aplicación depende de ValidationHandler como su middleware de aplicación. La devolución de llamada no-op impide que se alcance la ruta fail-closed ErrAuthenticationServiceMissing y reenvía la solicitud a manejadores protegidos que pueden requerir una clave API, un token OAuth u otro esquema de seguridad. Este problema se corrige en la versión 0.144.0. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 13, 2026
Action Type Old Value New Value Added Reference https://github.com/getkin/kin-openapi/security/advisories/GHSA-r277-6w6q-xmqw Added SSVC {'id': 'CVE-2026-73501', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-13T13:06:12.716245Z'} -
New CVE Received by [email protected]
Aug. 12, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'getkin', 'product': 'kin-openapi', 'versions': [{'status': 'affected', 'version': '< 0.144.0'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-287 Added Reference https://github.com/getkin/kin-openapi/commit/f0407d53b0730280266f454b755010e7eeb985da Added Reference https://github.com/getkin/kin-openapi/releases/tag/v0.144.0 Added Reference https://github.com/getkin/kin-openapi/security/advisories/GHSA-r277-6w6q-xmqw