{"id":"CVE-2026-54603","title":"OAuth2 is a Ruby wrapper for the OAuth 2.0 and 2.1 authorization frameworks, including OpenID Connect (OIDC)","summary":"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,…","severity":"high","cvss":8.6,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N","cwe":["CWE-200","CWE-601"],"vendor":"oauth2","product":"oauth2","affected":["oauth2 >= 0.4.0, <= 2.0.21"],"patched":["oauth2 2.0.22"],"published":"2026-07-28","updated":"2026-09-09","sourceUpdated":"2026-09-09T20:50:00.950","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-54603","references":[{"url":"https://github.com/ruby-oauth/oauth2/commit/0f0a474f1b38453e119e660c2daca742d4378ce9","label":"security-advisories@github.com"},{"url":"https://github.com/ruby-oauth/oauth2/releases/tag/v2.0.22","label":"security-advisories@github.com"},{"url":"https://github.com/ruby-oauth/oauth2/security/advisories/GHSA-pp92-crg2-gfv9","label":"security-advisories@github.com"},{"url":"https://github.com/ruby-oauth/oauth2/security/advisories/GHSA-pp92-crg2-gfv9","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://github.com/advisories/GHSA-pp92-crg2-gfv9"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54603.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-54603"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2508093"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-54603"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54603"}],"tags":["nvd","ghsa","rubygems","csaf","vex","red-hat"],"epss":0.00434,"epssPercentile":0.37182,"aliases":["GHSA-pp92-crg2-gfv9"],"ecosystem":"rubygems","ingestedAt":"2026-07-28T16:37:04.370Z","slug":"CVE-2026-54603","body":"## Overview\n\nOAuth2 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-54603)\n\nAffected packages:\n\n- `oauth2 >= 0.4.0, <= 2.0.21`\n\nPatched in:\n\n- `oauth2 2.0.22`\n\nSource: https://github.com/advisories/GHSA-pp92-crg2-gfv9\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat 3scale API Management Platform 2 · no fix planned: Red Hat 3scale API Management Platform 2 · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-54603.json)","depth":"twilight","depthScore":47,"depthScoreParts":{"impact":47.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}