CVE-2026-27191 Feathers: Open Redirect in OAuth callback enables account takeover
Attackers can steal access tokens via URL authority injection in OAuth callbacks, leading to full account takeover in Feathers.js applications.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-27191?
CVE-2026-27191 is a high-severity vulnerability in feathersjs feathers, published on 21 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. Versions 5.0.39 and below the redirect query parameter is appended to the base origin without validation, allowing attackers to steal access tokens via URL authority injection. This leads to full account takeover, as the attacker obtains the victim's access token and can impersonate them. The application constructs the final redirect URL by concatenating the base origin with the user-supplied redirect parameter. This is exploitable when the origins array is configured and origin values do not end with /. An attacker can supply @attacker.com as the redirect value results in https://[email protected]#access_token=..., where the browser interprets attacker.com as the host, leading to full account takeover. This issue has been fixed in version 5.0.40.
Weakness: CWE-601
Which versions are affected by CVE-2026-27191?
2 open source packages ship an affected version, including @feathersjs/authentication-oauth. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@feathersjs/authentication-oauth npm | All versions | 5.0.40 |
@feathersjs/authentication-oauth npm | All versions | 5.0.40 |
Products include Feathersjs Feathers.
How do I fix CVE-2026-27191?
Upgrade @feathersjs/authentication-oauth to 5.0.40 or later.
Is CVE-2026-27191 being exploited?
There is no known exploitation of CVE-2026-27191 in the wild and no public exploit code.
Other vulnerabilities in feathersjs feathers
- CVE-2026-29792 Feathersjs has an OAuth Callback Account Takeover
- CVE-2026-29793 NoSQL Injection via WebSocket id Parameter in MongoDB Adapter
- CVE-2026-27193 Feathers exposes internal headers via unencrypted session cookie
- CVE-2026-27192 Feathers has an origin validation bypass via prefix matching
- CVE-2023-37899 feathersjs socket handler allows abusing implicit toString
Sources
Also known as GHSA-ppf9-4ffw-hh4p.