What is CVE-2026-44476?
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.
The record classifies CVE-2026-44476 under weakness classes CWE-287, CWE-1390. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 41 days ago.
Severity and exploitation probability
- CVSS v4.0 base score
- 6.3 — Medium (derived from score)
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 - CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 3.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-08-25
Is CVE-2026-44476 being exploited?
It currently carries a trending score of 30 in the Threadlinqs vulnerability feed.
Affected products and versions
- doorkeeper-gem: doorkeeper-openid_connect
Affected software packages:
rubygems:doorkeeper-openid_connect— patched in 1.10.0
How to fix CVE-2026-44476
Fixed versions are recorded for 1 package: rubygems:doorkeeper-openid_connect 1.10.0. No vendor patch reference has been recorded for CVE-2026-44476 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-44476
No threat campaign in the Threadlinqs corpus currently references CVE-2026-44476, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, GitHub Security Advisories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.