{"cve":"CVE-2026-44476","nvd":{"published":"2026-08-25T23:17:04.400","modified":"2026-09-09T21:09:13.080","status":"Deferred","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.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","score":6.3},"cvss_v3":null,"cwes":["CWE-287","CWE-1390"],"references":["https://github.com/doorkeeper-gem/doorkeeper-openid_connect/commit/561af83dcf","https://github.com/doorkeeper-gem/doorkeeper-openid_connect/security/advisories/GHSA-m6vc-f87m-cc2h","https://github.com/doorkeeper-gem/doorkeeper-openid_connect/security/advisories/GHSA-m6vc-f87m-cc2h"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:17.453294893+00:00"},"epss":{"cve":"CVE-2026-44476","score":0.00564,"percentile":0.46913,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-m6vc-f87m-cc2h","url":"https://osv.dev/vulnerability/GHSA-m6vc-f87m-cc2h","summary":"Doorkeeper Openid Connect: Dynamic Client Registration feature creates public clients with client_secret","modified":"2026-06-09T12:00:16.158054391Z","packages":[{"ecosystem":"RubyGems","name":"doorkeeper-openid_connect","purl":"pkg:gem/doorkeeper-openid_connect","ranges":[">=1.9.0 <1.10.0"],"fixed":["1.10.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}