CVE-2026-54603
HIGH
MEDIUM
Priority: 0.04
BB Relevance:
77/100
Published: 2026-07-28
Modified: 2026-10-23
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
No Auth
No Interaction
Conf. Impact
Scope Change
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
None
UI:
None
S:
Changed
C:
High
I:
None
A:
None
Description
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.