CVE-2026-29792

The record

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. From 5.0.0 to before 5.0.42, an unauthenticated attacker can send a crafted GET request directly to /oauth/:provider/callback with a forged profile in the query string. The OAuth service's authentication payload has a fallback chain that reaches params.query (the raw request query) when Grant's session/state responses are empty. Since the attacker never initiated an OAuth authorize flow, Grant has no session to work with and produces no response, so the fallback fires. The forged profile then drives entity lookup and JWT minting. The attacker gets a valid access token for an existing user without ever contacting the OAuth provider. This vulnerability is fixed in 5.0.42.

Affected packages

Related vulnerabilities

• GHSA-wg9x-qfgw-pxhj Feathers has an OAuth Callback Account Takeover issue Same vulnerability
• CVE-2026-27193 Feathersjs is a framework for creating web APIs and real-time applications with… Also affects @feathersjs/authentication-oauth
• CVE-2026-27191 Feathersjs is a framework for creating web APIs and real-time applications with… Also affects @feathersjs/authentication-oauth
• CVE-2026-27192 Feathersjs is a framework for creating web APIs and real-time applications with… Also affects @feathersjs/authentication-oauth
• GHSA-9m9c-vpv5-9g85 Feathers exposes internal headers via unencrypted session cookie Also affects @feathersjs/authentication-oauth
• GHSA-mp4x-c34x-wv3x Feathers has an origin validation bypass via prefix matching Also affects @feathersjs/authentication-oauth
• GHSA-ppf9-4ffw-hh4p Feathers has an open redirect in OAuth callback enables account takeover Also affects @feathersjs/authentication-oauth
• CVE-2026-114638 Traefik v3.7.0 before v3.7.14 contains an improper authentication vulnerability in the… CWE-287