CVE-2026-44476
Fix: doorkeeper-gem/doorkeeper-openid_connect@561af83CVE-2026-44476 is a Improper Authentication vulnerability in doorkeeper-openid_connect. O3 Security confirms whether CVE-2026-44476 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Doorkeeper OpenID Connect: Dynamic Client Registration feature creates public clients with client_secret
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-44476.
Real-World Exposure
doorkeeper-openid_connectReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Doorkeeper is an OAuth 2 provider for Ruby on Rails. In version 1.9.0, an attacker who knows only a dynamically registered client's client_id, which is public information, can authenticate as that client at the token endpoint and obtain an access token without providing its client_secret. This occurs because the Dynamic Client Registration feature creates applications with confidential: false hard-coded, even though the registration response returns a client_secret and advertises support for the client_secret_basic and client_secret_post authentication methods; since Doorkeeper treats a blank or missing secret as valid for non-confidential (public) clients, the secret is never verified. Only projects that have explicitly enabled Dynamic Client Registration, which is disabled by default, are affected. This issue is fixed in version 1.10.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | doorkeeper-openid_connect | ≥ 1.9.0&&< 1.10.0 | 1.10.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for doorkeeper-openid_connect. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update doorkeeper-openid_connect to 1.10.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44476 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-44476 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-44476. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-44476 in your dependencies?
O3 detects CVE-2026-44476 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.