CVE-2026-114607

better-auth: OAuth state can be used as a Magic Link to sign in as another user

State
Published
Severity
9.1 Critical
Published
Oct 22, 2026
Updated
Oct 23, 2026
Reserved
Oct 21, 2026

Read the record on cve.org

Description

Better Auth is an authentication and authorization library for TypeScript. From 1.4.0-beta.18 until 1.7.7, deployments that enable Magic Link with storeToken set to plain, or with storeToken set to hashed and the global verification.storeIdentifier setting also set to hashed, enable a built-in social or Generic OAuth provider, and use account.storeStateStrategy set to database can accept an OAuth sign-in state value as a Magic Link token. These settings can cause Magic Link verification records and OAuth state to resolve to the same stored identifier, allowing an unauthenticated attacker to start OAuth sign-in for a known email address and redeem the returned state through Magic Link without controlling the mailbox or completing the provider callback. The attacker can obtain a normal session for an existing user, or create an account incorrectly marked as email verified when sign-up is enabled. This issue is fixed in version 1.7.7.

Scores

CVSSScoreVectorSource
3.19.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NGitHub_M

Weaknesses

Affected Products

ProductVersions
better-authbetter-auth
  • >= 1.4.0-beta.18, < 1.7.7Affected

References

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