CVE-2026-54603

ruby-oauth oauth2VulnerabilityCVSS 8.6

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.

No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.

Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.

CVE-2026-54603 ruby-oauth oauth2 Vulnerability

Severity metrics

CVSS 3.1 : 8.6 HIGH

Attack vectorNetwork (remote)

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeChanged

Confidentiality impactHigh

Integrity impactNone

Availability impactNone

Vector: AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

Affected & fixed versions by distribution

Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.

No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.

Sources

Advisory NVD CVE.org

Published 2026-07-28 · source: NVD