---
id: CVE-2026-54603
title: >-
  OAuth2 is a Ruby wrapper for the OAuth 2.0 and 2.1 authorization frameworks,
  including OpenID Connect (OIDC)
summary: >-
  OAuth2 is a Ruby wrapper for the OAuth 2.0 and 2.1 authorization frameworks,
  including OpenID Connect (OIDC). From 0.4.0 to 2.0.21, a protocol-relative
  redirect Location returned to OAuth2::Client#request overrides the request
  authority,…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N'
cwe:
  - CWE-200
  - CWE-601
vendor: oauth2
product: oauth2
affected:
  - 'oauth2 >= 0.4.0, <= 2.0.21'
patched:
  - oauth2 2.0.22
published: '2026-07-28'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T20:50:00.950'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-54603'
references:
  - url: >-
      https://github.com/ruby-oauth/oauth2/commit/0f0a474f1b38453e119e660c2daca742d4378ce9
    label: security-advisories@github.com
  - url: 'https://github.com/ruby-oauth/oauth2/releases/tag/v2.0.22'
    label: security-advisories@github.com
  - url: >-
      https://github.com/ruby-oauth/oauth2/security/advisories/GHSA-pp92-crg2-gfv9
    label: security-advisories@github.com
  - url: >-
      https://github.com/ruby-oauth/oauth2/security/advisories/GHSA-pp92-crg2-gfv9
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-pp92-crg2-gfv9'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54603.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-54603'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2508093'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-54603'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-54603'
tags:
  - nvd
  - ghsa
  - rubygems
  - csaf
  - vex
  - red-hat
epss: 0.00594
epssPercentile: 0.46137
aliases:
  - GHSA-pp92-crg2-gfv9
ecosystem: rubygems
ingestedAt: '2026-07-28T16:37:04.370Z'
---

## Overview

OAuth2 is a Ruby wrapper for the OAuth 2.0 and 2.1 authorization frameworks, including OpenID Connect (OIDC). From 0.4.0 to 2.0.21, a protocol-relative redirect Location returned to OAuth2::Client#request overrides the request authority, so the bearer Authorization header is sent to an attacker-controlled host, leaking the credential. This issue is fixed in version 2.0.22.

## Remediation

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

## Package advisory (CVE-2026-54603)

Affected packages:

- `oauth2 >= 0.4.0, <= 2.0.21`

Patched in:

- `oauth2 2.0.22`

Source: https://github.com/advisories/GHSA-pp92-crg2-gfv9

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat 3scale API Management Platform 2 · no fix planned: Red Hat 3scale API Management Platform 2 · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54603.json)