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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

6.3 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-44476: 0.56% estimated exploitation activity in the next 30 days; percentile 46.94 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact The DynamicClientRegistrationController#register action hard-codes confidential: false when creating applications (dynamicclientregistrationcontroller.rb:18-25), yet the response includes a clientsecret and advertises tokenendpointauthmethodssupported: ["clientsecretbasic", "clientsecretpost"]. Because Doorkeeper's Application.byuidandsecret treats a blank/missing secret as valid for non-confidential (public) clients, an attacker who knows only the clientid (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 1. Enable dynamic client registration in the initializer 2. POST /oauth/registration with clientname, redirecturis, and scope 3. Observe: response returns clientsecret, but the created Doorkeeper::Application has confidential: false 4. Call…

Published by the source

4 Jun 2026, 14:37 UTC

Last modified by the source

9 Jun 2026, 11:57 UTC

Source last checked

26 Oct 2026, 15:52 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-m6vc-f87m-cc2h

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# Patch Next advisory brief: CVE-2026-44476

Advisory: Doorkeeper Openid Connect: Dynamic Client Registration feature creates public clients with client_secret
IDs: CVE-2026-44476, GHSA-m6vc-f87m-cc2h
Record: https://patchnext.com/advisories/cve-2026-44476 (revision 1, source checked 26 Oct 2026, 15:52 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: doorkeeper-openid_connect 1.10.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems doorkeeper-openid_connect: affected >= 1.9.0, <= 1.9.0; fixed in 1.10.0

## Suggested inspection (read-only)
- RubyGems doorkeeper-openid_connect: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on doorkeeper-openid_connect.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-m6vc-f87m-cc2h (GitHub-reviewed advisory GHSA-m6vc-f87m-cc2h lists affected ranges: RubyGems doorkeeper-openid_connect >=1.9.0 <=1.9.0)

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