---
id: CVE-2026-107162
title: >-
  Express Gateway through 1.16.11 contains an authentication bypass
  vulnerability in the OAuth 2.0 refresh_token grant that fails to validate the
  token secret or issuing client
summary: >-
  Express Gateway through 1.16.11 contains an authentication bypass
  vulnerability in the OAuth 2.0 refresh_token grant that fails to validate the
  token secret or issuing client. Attackers with any valid client credentials
  and the identifie…
severity: medium
cvss: 6.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-287
vendor: ExpressGateway
product: express-gateway
affected:
  - express-gateway <= 1.16.11
published: '2026-10-07'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T13:17:19.963'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-107162'
references:
  - url: 'https://github.com/ExpressGateway/express-gateway'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/ExpressGateway/express-gateway/blob/45612814d12f65889ef3bdf80b2ed7ab9b557736/lib/policies/oauth2/oauth2-server.js#L221-L247
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/ExpressGateway/express-gateway/blob/45612814d12f65889ef3bdf80b2ed7ab9b557736/lib/services/tokens/token.service.js#L100-L136
    label: disclosure@vulncheck.com
  - url: 'https://github.com/ExpressGateway/express-gateway/issues/1076'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/express-gateway-through-1.16.11-oauth-2.0-refresh-token-validation-bypass
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-07T13:31:04.597Z'
---

## Overview

Express Gateway through 1.16.11 contains an authentication bypass vulnerability in the OAuth 2.0 refresh_token grant that fails to validate the token secret or issuing client. Attackers with any valid client credentials and the identifier portion of another user's refresh token can obtain that user's access token and impersonate them against oauth2-protected APIs.

## Remediation

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