What’s Vulnerable › Vulnerabilities
CVE-2026-66816: Microsoft SQL Server Security Feature Bypass Vulnerability
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.0% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-08 · updated 2026-10-31
- Weakness: CWE-778
Description
Insufficient logging in SQL Server allows an authorized attacker to bypass a security feature over a network.
Affected products
- Microsoft Sql Server 2022: before 16.0.1200.5; from 16.0.4003.1 before 16.0.4275.2 — fixed in 16.0.1200.5, 16.0.4275.2
- Microsoft Sql Server 2025: before 17.0.1135.8; from 17.0.4006.2 before 17.0.4085.5 — fixed in 17.0.1135.8, 17.0.4085.5
- Microsoft SQL Server 2022 (CU 26): from 16.0.0.0 before 16.0.4275.2 — fixed in 16.0.4275.2
- Microsoft SQL Server 2022 (GDR): from 16.0.0 before 16.0.1200.5 — fixed in 16.0.1200.5
- Microsoft SQL Server 2025 (CU8): from 17.0.0.0 before 17.0.4085.5 — fixed in 17.0.4085.5
- Microsoft SQL Server 2025 for x64-based Systems (GDR): from 17.0.1050.2 before 17.0.1135.8 — fixed in 17.0.1135.8
How to fix
Upgrade to a fixed version: Microsoft Sql Server 2022 16.0.1200.5, 16.0.4275.2; Microsoft Sql Server 2025 17.0.1135.8, 17.0.4085.5; Microsoft SQL Server 2022 (CU 26) 16.0.4275.2; Microsoft SQL Server 2022 (GDR) 16.0.1200.5; Microsoft SQL Server 2025 (CU8) 17.0.4085.5; Microsoft SQL Server 2025 for x64-based Systems (GDR) 17.0.1135.8. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-66816 or the next vulnerability affects your stack