CVE-2026-53517 Better Auth OAuth Provider: Refresh Token Rotation Race Condition Allows Concurrent Replay and Token Family Forking

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 Better Auth OAuth Provider: Refresh Token Rotation Race Condition Allows Concurrent Replay and Token Family Forking

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-2026-53515

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...

CVE-2026-53515 Better Auth: Privilege escalation via SSO provider registration: missing admin role check in @better-auth/sso

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...

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...

EUVD-2026-44735

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 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-2026-53512 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

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...

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 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 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-2026-53513

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...

CVE-2026-53513 Better Auth: Server-side request forgery via unvalidated OIDC endpoints on @better-auth/sso provider registration

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 Better Auth: Server-side request forgery via unvalidated OIDC endpoints on @better-auth/sso provider registration

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 Better Auth: Server-side request forgery via unvalidated OIDC endpoints on @better-auth/sso provider registration

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-2026-47164

A flaw was found in Vaultwarden, a Bitwarden-compatible server. The Single Sign-On SSO login process, when configured to automatically link sign-ups by email, failed to verify the email address for existing user accounts. This allowed a remote attacker, by controlling an Identity Provider IdP...