Information disclosure in ruby-oauth oauth2
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure, Spoofing
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-200 and CWE-601.
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, so the bearer Authorization header is sent to an attacker-controlled host, leaking the credential. This issue is fixed in version 2.0.22.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ruby-oauth | oauth2 | 0.4.0 to before 2.0.22 | 2.0.22 | Patch available | CNA |
| — | oauth2 (RubyGems) | 0.4.0 to before 2.0.22 | 2.0.22 | Patch available | GHSA-pp92-crg2-gfv9 |
- oauth2 Vendorruby-oauth Affected 0.4.0 to before 2.0.22 Fixed in 2.0.22 Patch available CNA
- oauth2 (RubyGems) Vendor— Affected 0.4.0 to before 2.0.22 Fixed in 2.0.22 Patch available GHSA-pp92-crg2-gfv9
Remediation
- Fix · CNA oauth2 (ruby-oauth) Fixed in 2.0.22
- Fix · GHSA-pp92-crg2-gfv9 oauth2 (RubyGems) Fixed in 2.0.22 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat 3scale API Management Platform 2 | Affected | No fix yet |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-54603
- 2026-10-03 Alias added: GHSA-pp92-crg2-gfv9
References
More ruby-oauth vulnerabilities
- TI-2026-39438 OAuth: Cross-origin token-request redirects can expose signed request metadata CVSS 3.1HIGH 7.2
Sources
- CVE-2026-54603 · CVE Program
- CVE-2026-54603 · NVD
- FIRST EPSS
- GHSA-pp92-crg2-gfv9 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-54603 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences