CVE-2026-53513

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: 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.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

• https://github.com/better-auth/better-auth/commit/37f60cb176cb53147da7dfd5ec15afa5b486e81e
• https://github.com/better-auth/better-auth/pull/9574
• https://github.com/better-auth/better-auth/releases/tag/v1.6.11
• https://github.com/better-auth/better-auth/security/advisories/GHSA-5rr4-8452-hf4v