CVE-2026-54603
OAuth2::Client#request: Protocol-relative redirect Location overrides authority, leaking bearer Authorization to attacker host
CVSS Score
8.6
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-200 CWE-601 |
| Vendor | ruby-oauth |
| Product | oauth2 |
| Published | Jul 28, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None
Affected Versions
ruby-oauth / oauth2
>= 0.4.0, < 2.0.22