What is CVE-2026-66309?

CVE-2026-66309 is a critical-severity vulnerability in Microsoft Azure SQL Database, classified under Improper Access Control. CVSS score: 9.1/10. Published 2026-08-20.

How severe is CVE-2026-66309?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Microsoft Azure SQL Database

CVE-2026-66309

Improper access control in Azure SQL Database allows an authorized attacker to elevate privileges over a network.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

Affected products

Microsoft Azure Sql Database

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

secure@microsoft.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-66309?: CVE-2026-66309 is a critical-severity vulnerability in Microsoft Azure SQL Database, classified under Improper Access Control. CVSS score: 9.1/10. Published 2026-08-20.
How severe is CVE-2026-66309?: Critical severity. CVSS v3 base score is 9.1 out of 10.