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.
Exploitability
AV:NAC:LPR:LUI:NScope
S:CImpact
C:HI:HA:N9.6/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N