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

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...

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

NPM: Better Auth: OAuth refresh-token replay via missing client authentication on oidc-provider and mcp plugins vulnerability discovered by ? in WordPress Npm better-auth versions 1.6.11...

CVE-2026-50631

A race condition in AbstractOAuthDataProvider allows concurrent requests using the same Refresh Token to bypass single-use semantics and generate multiple valid Access Tokens, when 'recycleRefreshTokens' is set to false. A leaked refresh token can be replayed concurrently by multiple attackers or...

keycloak: Keycloak: Unauthorized account access via replayed refresh tokens after cluster restart

A flaw was found in Keycloak. When revokeRefreshToken=true is enabled and persistent session storage is in use, a server restart can reset internal timing mechanisms. This allows a remote attacker, who has previously captured a user's refresh token, to replay that token even after it has been...