ruby-oauth oauth2 up to 2.0.21 Client OAuth2::Client#request redirect

Summaryinfo

A vulnerability was found in ruby-oauth oauth2 up to 2.0.21. It has been declared as problematic. The affected element is the function OAuth2::Client#request of the component Client. The manipulation results in redirect. This vulnerability was named CVE-2026-54603. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in ruby-oauth oauth2 up to 2.0.21. It has been classified as problematic. Affected is the function OAuth2::Client#request of the component Client. The manipulation with an unknown input leads to a redirect vulnerability. CWE is classifying the issue as CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. This is going to have an impact on integrity. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-54603 since 06/15/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1204.001.

Upgrading to version 2.0.22 eliminates this vulnerability.

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Productinfo

Type

• Programming Language Software

Vendor

• ruby-oauth

Name

• oauth2

Version

• 2.0.0
• 2.0.1
• 2.0.2
• 2.0.3
• 2.0.4
• 2.0.5
• 2.0.6
• 2.0.7
• 2.0.8
• 2.0.9
• 2.0.10
• 2.0.11
• 2.0.12
• 2.0.13
• 2.0.14
• 2.0.15
• 2.0.16
• 2.0.17
• 2.0.18
• 2.0.19
• 2.0.20
• 2.0.21

Website

• Product: https://github.com/ruby-oauth/oauth2/

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CPE 2.2info

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