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Vulnerability · Published Oct 22, 2026 · Assigned by GitHub_M

CVE-2026-114607better-auth: OAuth state can be used as a Magic Link to sign in as another user

Critical 9.1

In plain English

A critical-severity improper authentication in better-auth from better-auth. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.4%top 63.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npmbetter-auth1.7.7GHSA-965c-763c-88jm

Affected products (as reported)

VendorProductVersions
better-auth better-auth >= 1.4.0-beta.18, < 1.7.7

Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References