CVE-2026-66820: SQL Server Elevation of Privilege Vulnerability

Overview

Severity

High (CVSS 8.8)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Category

Elevation of Privilege

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Sep

Released

2026-09-08

Description

Improper neutralization of special elements used in an sql command ('sql injection') in SQL Server allows an authorized attacker to elevate privileges over a network.

FAQ

What privileges could be gained by an attacker who successfully exploited the vulnerability? An attacker who successfully exploited this vulnerability could gain SQL sysadmin privileges. How could an attacker exploit this vulnerability? An authenticated attacker with explicit permissions could exploit the vulnerability by logging in to the SQL server and could then elevate their privileges to sysadmin.

Affected Products (8)

SQL Server

• Microsoft SQL Server 2017 for x64-based Systems (GDR)
• Microsoft SQL Server 2019 for x64-based Systems (GDR)
• Microsoft SQL Server 2017 for x64-based Systems (CU 31)
• Microsoft SQL Server 2022 for x64-based Systems (GDR)
• Microsoft SQL Server 2025 for x64-based Systems (GDR)
• Microsoft SQL Server 2019 for x64-based Systems (CU 32)
• Microsoft SQL Server 2022 for x64-based Systems (CU 26)
• Microsoft SQL Server 2025 for x64-based Systems (CU8)

Security Updates (8)

• 5122775
• 5122773
• 5122774
• 5122771
• 5122770
• 5122772
• 5122768
• 5122769

Acknowledgments

<a href="https://www.linkedin.com/in/fabianoamorim/">Fabiano Amorim</a> with <a href="https://pythian.com/">Pythian</a>

Revision History

• 2026-09-08: Information published.