Better-auth
- 8
- vulnerabilities tracked
- 2
- critical
- 15 July 2026
- latest publication
cve
Vulnerability watch
idvulnerabilityseveritypublished
CVE-2026-45337Better 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 short-circuit when userId is unset, allowing an authenticated attacker who learns a valid user_code to bind the polling device to the attacker's account or deny the legitimate flow. This issue is fixed in version 1.6.11.Better-auth Better Auth High CVSS 7.6 CVE-2026-53512Better 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 refresh_token grant authenticates only possession of the bound refreshToken row and matching client_id, without verifying the confidential client's client_secret, allowing an attacker with a valid refresh_token to mint access tokens and rotated refresh tokens through /api/auth/oauth2/token or /api/auth/mcp/token. The @better-auth/oauth-provider package is not affected. This issue is fixed in version 1.6.11.Better-auth Better Auth Critical CVSS 9.1 CVE-2026-53513Better 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: true is set, store them on the ssoProvider row without origin validation, and fetch them during OIDC callback, allowing non-blind server-side request forgery and possible account linking when trustEmailVerified: true is configured. This issue is fixed in version 1.6.11.Better-auth Better-auth\/sso Critical CVSS 9.6 CVE-2026-53514Better 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, rejectInvitation, getInvitation, and listUserInvitations recipient endpoints use session.user.email and an invitation ID without sufficient verified-email ownership proof, allowing a user with an unverified session for the invited email address to accept an organization invitation after obtaining the invitation ID. This issue is fixed for the original default behavior in version 1.6.11, while 1.6.14 restored compatibility for built-in opaque invitation IDs and leaves affected configurations requiring secure options.Better-auth Better Auth High CVSS 7.7 CVE-2026-53515Better 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 and does not require an owner or admin role, allowing attacker-controlled OIDC or SAML providers to drive /sso/callback/{providerId} organization provisioning. This issue is fixed in version 1.6.11.Better-auth Better-auth\/sso High CVSS 7.1 CVE-2026-53516Better 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 email_verified: true without requiring the local user row's emailVerified field to also be true, allowing an attacker who pre-registers a victim email through /sign-up/email to bind the victim's OAuth identity to the attacker's account. The same primitive affects one-tap, and emailAndPassword.requireEmailVerification: true does not mitigate the link-time verification change. This issue is fixed in version 1.6.11.Better-auth Better Auth High CVSS 8.3 CVE-2026-53517Better 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 refresh_token grant performs a non-atomic read, validate, revoke, and mint sequence on the oauthRefreshToken row, allowing concurrent requests with the same parent refresh token to pass the revoked check and create forked refresh-token families; the vulnerable range also includes embedded better-auth plugin versions before 1.6.0. This issue is fixed in version 1.6.11.Better-auth Better-auth\/oauth-provider High CVSS 8.1 CVE-2026-53518Better 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 authorization_code grant redeems a single-use authorization code through a non-atomic find-then-delete sequence, allowing two concurrent requests to pass the read step and mint independent access tokens, refresh tokens, and ID tokens; legacy /oauth2/token and /mcp/token paths in oidc-provider and mcp plugins share the same primitive. This issue is fixed in version 1.6.11.Better-auth Better-auth\/oauth-provider High CVSS 8.1