The CVSS 9.1 on CVE-2026-66309 is technically accurate but analytically misleading. This isn't a SQL injection flaw or authentication bypass—it's an authorization gap that likely emerged from the interaction of multiple permission grants that individually look reasonable but collectively create an unintended escalation path within Azure SQL's layered permission model (server roles, database roles, contained users, Azure AD principals, row-level and column-level security). The critical severity score reflects the exploitation reliability, not the presence of a traditional code defect.
The 'authorized attacker' qualifier masks the real attack surface. In enterprise Azure SQL deployments, 'authorized' encompasses far more than DBAs—it includes service principals for every app service, automation runbooks, Logic Apps, Azure Functions, and third-party integrations, many provisioned with broader permissions than necessary because least-privilege in cloud databases is genuinely difficult to operationalize. Anyone with valid credentials to any of these principals could potentially exploit this escalation path.
The deeper question is whether this reflects a flaw in Azure SQL's permission enforcement logic affecting all tenants, or primarily enables exploitation of pre-existing over-permissioned deployments. Evidence points toward the latter: Azure SQL's permission model is a direct transliteration of on-prem SQL Server role semantics into a multi-tenant, network-accessible environment. SQL Server's ownership chaining, EXECUTE AS, and server-level versus database-level role separation were designed for single-machine DBA-controlled stacks. Layering Azure AD principals, contained database users, and publicly routable endpoints on that foundation multiplies failure modes that the cloud migration teams apparently didn't carry forward from decades of SQL Server permission escalation research.
The patch will close this specific escalation path, but the structural permission debt remains. Organizations running over-permissioned service principals, automation identities, and application accounts will still have those grants—they'll just be missing this particular combination. This creates a false sense of resolution: the CVE is addressed, the CVSS drops, the security report turns green, but the systemic permission complexity that made this vulnerability severe remains. Treat the patch as one debt payment on an overdue balance, not a final resolution. Your real work begins after Microsoft ships the fix—conduct a credential audit, tighten service principal permissions, and assume network-layer controls alone never provided the isolation you thought they did.