Budibase is an open-source low-code platform. Prior to 3.39.25, POST /api/global/auth/:tenantId/login incremented the failure counter in packages/worker/src/api/controllers/global/auth.ts only for existing users, while packages/worker/src/middleware/emailLockout.ts returned X-Account-Locked and Retry-After only for locked identifiers. An unauthenticated attacker could compare the response after repeated failures to enumerate valid email addresses and temporarily lock valid accounts. This issue is fixed in version 3.39.25.