Vulnerability 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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/ruby-oauth/oauth2/commit/0f0a474f1b38453e119e660c2daca742d437
- https://github.com/ruby-oauth/oauth2/releases/tag/v2.0.22
- https://github.com/ruby-oauth/oauth2/security/advisories/GHSA-pp92-crg2-gfv9
- https://github.com/ruby-oauth/oauth2/security/advisories/GHSA-pp92-crg2-gfv9
FAQ
What is CVE-2026-54603?
CVE-2026-54603 is a vulnerability with a CVSS score of 8.6 (HIGH). 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#req...
How severe is CVE-2026-54603?
CVE-2026-54603 has been rated HIGH with a CVSS base score of 8.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-54603?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.