GHSA-v64w-49xw-qq89
MEDIUMPossible user mocking that bypasses basic authentication
EPSS Exploitation Probability
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
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
next-authnpmDescription
Impact
next-auth applications prior to version 4.24.5 that rely on the default Middleware authorization are affected.
A bad actor could create an empty/mock user, by getting hold of a NextAuth.js-issued JWT from an interrupted OAuth sign-in flow (state, PKCE or nonce).
Manually overriding the next-auth.session-token cookie value with this non-related JWT would let the user simulate a logged in user, albeit having no user information associated with it. (The only property on this user is an opaque randomly generated string).
This vulnerability does not give access to other users' data, neither to resources that require proper authorization via scopes or other means. The created mock user has no information associated with it (ie. no name, email, access_token, etc.)
This vulnerability can be exploited by bad actors to peek at logged in user states (e.g. dashboard layout).
Note: Regardless of the vulnerability, the existence of a NextAuth.js session state can provide simple authentication, but not authorization in your applications. For role-based access control, you can check out our guide.
Patches
We patched the vulnerability in next-auth v4.24.5. To upgrade, run one of the following:
npm i next-auth@latest
yarn add next-auth@latest
pnpm add next-auth@latest
Workarounds
Upgrading to latest is the recommended way to fix this issue. However, using a custom authorization callback for Middleware, developers can manually do a basic authentication:
// middleware.ts
import { withAuth } from "next-auth/middleware"
export default withAuth(/*your middleware function*/, {
// checking the existence of any property - besides `value` which might be a random string - on the `token` object is sufficient to prevent this vulnerability
callbacks: { authorized: ({ token }) => !!token?.email }
})
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | next-auth | all versions | 4.24.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for next-auth. 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.
Fix
Update next-auth to 4.24.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-v64w-49xw-qq89 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 pinpoints whether GHSA-v64w-49xw-qq89 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-v64w-49xw-qq89. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-v64w-49xw-qq89 in your dependencies?
O3 detects GHSA-v64w-49xw-qq89 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.