CVE-2026-53517

Better Auth is an authentication and authorization library for TypeScript. From 1.4.8-beta.7 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint on the refreshtoken grant performs a non-atomic read, validate, revoke, and mint sequence on the oauthRefreshToken row, allowing...

CVE-2026-53518

Better Auth is an authentication and authorization library for TypeScript. From 1.6.0 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint for the authorizationcode grant redeems a single-use authorization code through a non-atomic find-then-delete sequence, allowing two...

CVE-2026-53516

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, Better Auth's OAuth callback auto-link gate in handleOAuthUserInfo accepts implicit account linking when the OAuth provider asserts emailverified: true without requiring the local user row's emailVerified...

CVE-2026-53512

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the legacy oidcProvider and mcp plugins expose OAuth token endpoints whose refreshtoken grant authenticates only possession of the bound refreshToken row and matching clientid, without verifying the...

CVE-2026-53515

Better Auth is an authentication and authorization library for TypeScript. From 1.2.10 until 1.6.11, the @better-auth/sso plugin's POST /sso/register endpoint lets any organization member attach a new SSO provider to that organization because registerSSOProvider checks only for a membership row a...

EUVD-2026-44745

Better Auth is an authentication and authorization library for TypeScript. From 1.4.8-beta.7 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint on the refreshtoken grant performs a non-atomic read, validate, revoke, and mint sequence on the oauthRefreshToken row, allowing...

CVE-2026-53517

CVE-2026-53517 affects Better Auth’s oauth-provider (and related memory adapter) prior to version 1.6.11. The POST /oauth2/token refresh_token flow performs a non-atomic read–validate–revoke–mint sequence on the oauthRefreshToken row, allowing concurrent requests with the same parent refresh toke...

CVE-2026-45337

Better Auth (TypeScript library) vulnerability CVE-2026-45337 affects versions 1.6.0–1.6.10 in the deviceAuthorization plugin. The root cause is that the verification path does not claim ownership of the pending device code and the approve/deny checks short-circuit when userId is unset, allowing ...

CVE-2026-45337 Better Auth: Device authorization approve and deny accept any authenticated session while the user code is pending

Better Auth is an authentication and authorization library for TypeScript. From 1.6.0 until 1.6.11, the deviceAuthorization plugin treats any authenticated session as the owner of any pending device code because GET /device does not claim the row and POST /device/approve and POST /device/deny...

CVE-2026-53514 Better Auth: Unauthorized invitation acceptance via unverified email match in organization plugin

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, and in 1.6.14 and later when invitation IDs can be obtained outside the invited mailbox and requireEmailVerificationOnInvitation: true is not enabled, the organization plugin's acceptInvitation,...

CVE-2026-53514

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, and in 1.6.14 and later when invitation IDs can be obtained outside the invited mailbox and requireEmailVerificationOnInvitation: true is not enabled, the organization plugin's acceptInvitation,...

CVE-2026-53514 Better Auth: Unauthorized invitation acceptance via unverified email match in organization plugin

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, and in 1.6.14 and later when invitation IDs can be obtained outside the invited mailbox and requireEmailVerificationOnInvitation: true is not enabled, the organization plugin's acceptInvitation,...

CVE-2026-53512

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the legacy oidcProvider and mcp plugins expose OAuth token endpoints whose refreshtoken grant authenticates only possession of the bound refreshToken row and matching clientid, without verifying the...

CVE-2026-53512

CVE-2026-53512 affects Better Auth versions prior to 1.6.11, where the legacy oidcProvider and mcp plugins expose OAuth2 token endpoints that validate refresh_token grants without requiring the confidential client’s client_secret. An attacker with a valid refresh_token and the corresponding publi...

CVE-2026-53512 Better Auth: OAuth refresh-token replay via missing client authentication on oidc-provider and mcp plugins

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the legacy oidcProvider and mcp plugins expose OAuth token endpoints whose refreshtoken grant authenticates only possession of the bound refreshToken row and matching clientid, without verifying the...

CVE-2026-53518

Better Auth is an authentication and authorization library for TypeScript. From 1.6.0 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint for the authorizationcode grant redeems a single-use authorization code through a non-atomic find-then-delete sequence, allowing two...

CVE-2026-53518 Better Auth OAuth Provider: Race Condition in Authorization Code Exchange Enables Multi-Use Code Redemption

Better Auth is an authentication and authorization library for TypeScript. From 1.6.0 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint for the authorizationcode grant redeems a single-use authorization code through a non-atomic find-then-delete sequence, allowing two...

CVE-2026-53518

CVE-2026-53518 affects the Better Auth ecosystem, specifically the @better-auth/oauth-provider token endpoint for the authorization_code grant (and legacy paths via oidc-provider/mcp plugins). A race condition arises from a non-atomic find-then-delete when redeeming a single-use authorization cod...

EUVD-2026-44733

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the @better-auth/sso plugin's POST /sso/register and POST /sso/update-provider endpoints accept attacker-controlled oidcConfig.userInfoEndpoint, tokenEndpoint, and jwksEndpoint URLs when skipDiscovery: tru...

CVE-2026-53513

CVE-2026-53513 affects the @better-auth/sso plugin for Better Auth. When skipDiscovery: true is set, POST /sso/register and POST /sso/update-provider may store attacker-controlled oidcConfig.userInfoEndpoint, tokenEndpoint, and jwksEndpoint URLs without origin validation, leading to server-side r...