---
id: CVE-2026-100351
title: kin-openapi is a Go project for handling OpenAPI files
summary: >-
  kin-openapi is a Go project for handling OpenAPI files. From 0.144.0 until
  0.147.0, openapi3filter.ValidationHandler validates an operation selected from
  decoded URL.Path while a downstream gorilla/mux router configured with
  UseEncodedPa…
severity: high
cvss: 7.4
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-289
  - CWE-436
vendor: getkin
product: kin-openapi
affected:
  - 'kin-openapi >= 0.144.0, < 0.147.0'
published: '2026-10-15'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T17:17:07.520'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-100351'
references:
  - url: >-
      https://github.com/getkin/kin-openapi/commit/eda80e2676e9f577ceed2dd80e64f16083edb041
    label: security-advisories@github.com
  - url: 'https://github.com/getkin/kin-openapi/releases/tag/v0.147.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/getkin/kin-openapi/security/advisories/GHSA-23vg-4cjm-66q5
    label: security-advisories@github.com
  - url: >-
      https://github.com/getkin/kin-openapi/security/advisories/GHSA-23vg-4cjm-66q5
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T16:09:06.679638Z'
ingestedAt: '2026-10-15T16:13:10.881Z'
---

## Overview

kin-openapi is a Go project for handling OpenAPI files. From 0.144.0 until 0.147.0, openapi3filter.ValidationHandler validates an operation selected from decoded URL.Path while a downstream gorilla/mux router configured with UseEncodedPath can dispatch a different operation selected from URL.RawPath. When a public exact route and a protected parameterized route use the same method and overlap after decoding, an unauthenticated remote request containing an encoded path separator can be validated as public and then dispatched to the protected handler without invoking the configured AuthenticationFunc. The reachable path parameter is constrained to an encoded representation that decodes to the public literal route, and proxies that canonicalize the URI before forwarding prevent this specific mismatch. This issue is fixed in version 0.147.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.