How severe is CVE-2026-44476?

No CVSS score has been assigned to CVE-2026-44476 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-44476?

CVE-2026-44476 affects the following packages: doorkeeper-openid_connect (RubyGems). Ecosystems affected: RubyGems.

How do I fix CVE-2026-44476?

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.

How do I detect CVE-2026-44476 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for doorkeeper-openid_connect, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-44476 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-44476 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-44476 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-44476?

CVE-2026-44476 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 45th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-44476?

CVE-2026-44476 is classified as Improper Authentication (CWE-287), CWE-1390 (CWE-1390). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-44476 published, and has it been updated?

CVE-2026-44476 was published on August 25, 2026 and was last updated on September 11, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎 RubyGems

Not in CISA KEV

CVE-2026-44476 — doorkeeper-openid_connect

Fix: doorkeeper-gem/doorkeeper-openid_connect@561af83

CVE-2026-44476 is a Improper Authentication vulnerability in doorkeeper-openid_connect. A fix is available for doorkeeper-openid_connect — see the affected versions and patch details below.

Doorkeeper OpenID Connect: Dynamic Client Registration feature creates public clients with client_secret

Also known asGHSA-m6vc-f87m-cc2h

Published

Aug 25, 2026

Updated

Sep 11, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk+0.24%

Lower risk than most CVEs45th percentile — riskier than 45% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

💎doorkeeper-openid_connect

Real-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

Impact

The DynamicClientRegistrationController#register action hard-codes confidential: false when creating applications (dynamic_client_registration_controller.rb:18-25), yet the response includes a client_secret and advertises token_endpoint_auth_methods_supported: ["client_secret_basic", "client_secret_post"].

Because Doorkeeper's Application.by_uid_and_secret treats a blank/missing secret as valid for non-confidential (public) clients, an attacker who knows only the client_id (which is public information) can authenticate as the dynamically-registered client at the token endpoint.

Note that Dynamic Client Registration is opt-in feature which is disabled by default so only projects that explicitly enabled it are affected.

Steps to Reproduce

Enable dynamic client registration in the initializer
POST /oauth/registration with client_name, redirect_uris, and scope
Observe: response returns client_secret, but the created Doorkeeper::Application has confidential: false
Call Doorkeeper::Application.by_uid_and_secret(client_id, nil) — it returns the application (credentials bypass)
POST /oauth/token with grant_type=client_credentials and only client_id (no client_secret) — the token endpoint issues an access token without any secret verification

Patches

Patched in 1.10.0

Workarounds

Upgrade existing applications created with a Dynamic Client registration to have confidential: true

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`doorkeeper-openid_connect`	≥ 1.9.0&&< 1.10.0	1.10.0`bundle update doorkeeper-openid_connect --conservative`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for doorkeeper-openid_connect, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

### Impact The `DynamicClientRegistrationController#register` action hard-codes `confidential: false` when creating applications (dynamic_client_registration_controller.rb:18-25), yet the response includes a client_secret and advertises `token_endpoint_auth_methods_supported: ["client_secret_basic", "client_secret_post"]`. Because Doorkeeper's `Application.by_uid_and_secret` treats a blank/missing secret as valid for non-confidential (public) clients, an attacker who knows only the client_id (which is public information) can authenticate as the dynamically-registered client at the token endp

O3 Security · Impact-Aware SCA

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