User Interface (UI) Misrepresentation of Critical Information Affecting better-auth package, versions >=1.3.8-beta.3 <1.7.0-rc.3
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-BETTERAUTH-20875276
- published13 Oct 2026
- disclosed12 Oct 2026
- creditXlabAITeam, liangjs
Introduced: 12 Oct 2026
NewCVE-2026-109346 (opens in a new tab)How to fix?
Upgrade better-auth to version 1.7.0-rc.3 or higher.
Overview
better-auth is a The most comprehensive authentication library for TypeScript.
Affected versions of this package are vulnerable to User Interface (UI) Misrepresentation of Critical Information via the deviceAuthorization plugin's GET /device endpoint, which omits the requesting client_id and scope from the approval page response. An attacker initiates a device authorization request via /device/code, then tricks a signed-in user into approving the code on an approval page that shows no client identity or requested permissions. Once approved, the attacker redeems the code at /device/token to obtain a live session token, gaining read and write access to any data the user's account can access.
Note: This is only exploitable if the deviceAuthorization() plugin is explicitly enabled, an attacker can initiate a device request (i.e., validateClient is not configured or a valid public client is accessible), and the approval page does not independently surface server-checked client and scope information.
Users are not affected if the opt-in deviceAuthorization() plugin is not enable.