CVE-2026-66814: CWE-1220: Insufficient Granularity of Access Control in Microsoft Microsoft SQL Server 2017 (CU 31)
Description
CVE-2026-66814 is a high-severity vulnerability in Microsoft SQL Server 2017 (CU 31) involving insufficient granularity of access control. This flaw allows an authorized attacker to elevate privileges over a network. The vulnerability affects multiple specific builds of SQL Server 2017 and later versions up to certain fixed builds. An official fix is available from Microsoft.
CVSS v3.1
Score 8.8high
Affected software
Microsoft
Microsoft SQL Server 2017 (CU 31)
Microsoft
Microsoft SQL Server 2017 (GDR)
Microsoft
Microsoft SQL Server 2019 (CU 32)
Microsoft
Microsoft SQL Server 2019 (GDR)
Microsoft
Microsoft SQL Server 2022 (CU 26)
Microsoft
Microsoft SQL Server 2022 (GDR)
Microsoft
Microsoft SQL Server 2025 (CU8)
Microsoft
Microsoft SQL Server 2025 for x64-based Systems (GDR)
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability, identified as CWE-1220, concerns insufficient granularity of access control in Microsoft SQL Server 2017 (CU 31) and later versions. It permits an attacker with some level of authorization to escalate privileges remotely over a network connection. The CVSS 3.1 base score is 8.8, indicating high severity with impacts on confidentiality, integrity, and availability. The vulnerability affects multiple version ranges of SQL Server 2017 and subsequent releases prior to specific fixed builds. Microsoft has released an official fix to address this issue.
Potential Impact
An authorized attacker can exploit this vulnerability to elevate their privileges on the affected SQL Server instance remotely. This can lead to full compromise of the database server, including unauthorized access to sensitive data and potential disruption of service.
Mitigation Recommendations
An official fix is available from Microsoft. Users should apply the security updates provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66814 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-07-27T19:02:26.601Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66814","vendor":"Microsoft"}]
Threat ID: 6aa044c7acd9273b49fa7b05
Added to database: 09/08/2026, 17:24:23 UTC
Last enriched: 10/16/2026, 20:49:57 UTC
Last updated: 10/23/2026, 15:10:14 UTC
Views: 40
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