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📦 npm

GHSA-ppf9-4ffw-hh4p

Feathers has an open redirect in OAuth callback enables account takeover

Also known asCVE-2026-27191
Published
Feb 19, 2026
Updated
Feb 23, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk16th percentile+0.24%
0.00%0.25%0.50%0.75%0.0%0.0%0.0%0.0%0.3%Mar 26May 26Jun 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected
📦@feathersjs/authentication-oauth

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

Description

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:

// https://github.com/feathersjs/feathers/blob/dove/packages/authentication-oauth/src/service.ts#L158C3-L176C4
const { redirect } = query;
...
session.redirect = redirect;

// https://github.com/feathersjs/feathers/blob/dove/packages/authentication-oauth/src/strategy.ts#L98
const redirectUrl = `${redirect}${queryRedirect}`;

Where:

  • redirect = base origin from config (e.g., https://target.com)
  • queryRedirect = user input from ?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.

Credits: Abdelwahed Madani Yousfi (@vvxhid) / Edoardo Geraci (@b0-n0-b0) / Thomas Rinsma (@ThomasRinsma) From Codean Labs.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npm@feathersjs/authentication-oauthall versions5.0.40

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @feathersjs/authentication-oauth. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update @feathersjs/authentication-oauth to 5.0.40 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-ppf9-4ffw-hh4p is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-ppf9-4ffw-hh4p is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-ppf9-4ffw-hh4p. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Description 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: ```javascript // https://github.com/feathersjs/feathers/blob/dove/packages/authentication-oauth/src/service.ts#L158C3-L176C4 const { redirect } = query; ... session.redirect = redirect; /
O3 Security · Impact-Aware SCA

Is GHSA-ppf9-4ffw-hh4p in your dependencies?

O3 detects GHSA-ppf9-4ffw-hh4p across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.