CVE-2026-56082: Supabase - Unauthenticated Cross-Tenant Billing Log Tampering via public.record_build_time RPC

Capgo (Cap-go/capgo) before 12.128.2 contains an improper access control vulnerability in the SECURITY DEFINER PostgREST RPC function public.record_build_time, which is granted to the anon role and callable with only the public Supabase publishable (sb_publishable_*) anon key. An unauthenticated attacker can insert rows into public.build_logs for arbitrary organizations and, because the function uses ON CONFLICT (build_id, org_id) DO UPDATE, can overwrite existing usage/billing records by reusing the same build_id for a target org. This enables cross-tenant tampering of billing build logs and financial-impact denial of service by inflating billable build time.