CVE-2026-77488: Microsoft SQL Server Information Disclosure Vulnerability

Overview

Severity

Medium (CVSS 5.5)

CVSS Vector

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

Category

Information Disclosure

Exploit Status

Not Exploited

Exploitation Likelihood

Unlikely

Patch Tuesday

2026-Sep

Released

2026-09-08

Description

Integer underflow (wrap or wraparound) in SQL Server allows an authorized attacker to disclose information locally.

FAQ

What type of information could be disclosed by this vulnerability? An attacker who successfully exploited this vulnerability could potentially read portions of heap memory.

Affected Products (8)

SQL Server

• Microsoft SQL Server 2025 for x64-based Systems (CU8)
• Microsoft SQL Server 2022 for x64-based Systems (CU 26)
• 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)

Security Updates (8)

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

Acknowledgments

Microsoft Red Team

Revision History

• 2026-09-08: Information published.