CVE-2026-44476

MediumCVSS 6.3

Published: 25/08/2026(UTC)Updated: 09/09/2026(UTC)Translated: 26/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.32%

25th percentile - higher than 25% of all known CVEs

Summary

Doorkeeper version 1.9.0 has a vulnerability that allows an attacker who knows only a dynamically registered client's client_id, which is public, to authenticate as that client at the token endpoint and obtain an access token without providing its client_secret. This occurs because Dynamic Client Registration creates applications with confidential: false hard-coded, even though the registration response returns a client_secret and advertises support for client_secret_basic and client_secret_post. Only projects with Dynamic Client Registration enabled (disabled by default) are affected.

Risk Assessment

An attacker could impersonate a registered client and gain unauthorized access to OAuth-protected resources, potentially leading to data integrity and confidentiality breaches.

Recommendation

Upgrade to version 1.10.0 or later and consider disabling Dynamic Client Registration if not required.

Other vulnerabilities in Doorkeeper

CVE-2023-34246Medium
Doorkeeper, an OAuth 2 provider for Ruby on Rails / Grape, prior to version 5.6.6 automatically processes authorization requests without user consent for previously approved public clients. This creates a risk of impersonation.

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS