CVE-2026-27192

The record

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In versions 5.0.39 and below, origin validation uses startsWith() for comparison, allowing attackers to bypass the check by registering a domain that shares a common prefix with an allowed origin.The getAllowedOrigin() function checks if the Referer header starts with any allowed origin, and this comparison is insufficient as it only validates the prefix. This is exploitable when the origins array is configured and an attacker registers a domain starting with an allowed origin string (e.g., https://target.com.attacker.com bypasses https://target.com). On its own, tokens are still redirected to a configured origin. However, in specific scenarios an attacker can initiate the OAuth flow from an unauthorized origin and exfiltrate tokens, achieving full account takeover. This issue has bee fixed in version 5.0.40.

Affected packages

Related vulnerabilities

• GHSA-mp4x-c34x-wv3x Feathers has an origin validation bypass via prefix matching Same vulnerability
• GHSA-wg9x-qfgw-pxhj Feathers has an OAuth Callback Account Takeover issue Also affects @feathersjs/authentication-oauth
• CVE-2026-29792 Feathersjs is a framework for creating web APIs and real-time applications with… Also affects @feathersjs/authentication-oauth
• 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
• GHSA-9m9c-vpv5-9g85 Feathers exposes internal headers via unencrypted session cookie 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-2026-114125 Storybook is a frontend workshop for building user interface components and pages in… CWE-346