CVE-2026-54603
HIGHOAuth2::Client#request: Protocol-relative redirect Location overrides authority, leaking bearer Authorization to attacker host
Title source: cnaDescription
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.
References (3)
Core 3
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/ruby-oauth/oauth2/security/advisories/GHSA-pp92-crg2-gfv9
X_Refsource_Misc x_refsource_misc
https://github.com/ruby-oauth/oauth2/commit/0f0a474f1b38453e119e660c2daca742d4378ce9
X_Refsource_Misc x_refsource_misc
https://github.com/ruby-oauth/oauth2/releases/tag/v2.0.22
Scores
CVSS v3
8.6
EPSS
0.0027
EPSS Percentile
18.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-200
CWE-601
Status
published
Products (2)
ruby-oauth/oauth2
>= 0.4.0, < 2.0.22
rubygems/oauth2
0.4.0 - 2.0.22RubyGems
Published
Jul 28, 2026
Tracked Since
Jul 28, 2026