CVE-2026-66818: CWE-269: Improper Privilege Management in Microsoft Microsoft SQL Server 2017 (CU 31)
Description
CVE-2026-66818 is a high-severity vulnerability in Microsoft SQL Server 2017 (CU 31) involving improper privilege management. It allows an authorized attacker to elevate privileges over a network, potentially leading to full compromise of confidentiality, integrity, and availability. 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)
pkg:maven/com.microsoft.sqlserver/microsoft-sql-serverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability, identified as CWE-269 (Improper Privilege Management), affects multiple versions of Microsoft SQL Server 2017 and later. It permits an attacker with some level of authorization to escalate their privileges remotely, impacting the confidentiality, integrity, and availability of the system. The CVSS v3.1 base score is 8.8, indicating high severity. Microsoft has released an official fix to address this issue.
Potential Impact
An authorized attacker can exploit this vulnerability over a network to elevate their privileges, potentially gaining higher-level access than intended. This can lead to complete compromise of the affected SQL Server instance, including unauthorized data access, modification, or denial 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-2026-66818 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-2026-66818","vendor":"Microsoft"}]
Threat ID: 6aa044c9acd9273b49fa7b2c
Added to database: 09/08/2026, 17:24:25 UTC
Last enriched: 10/16/2026, 20:50:04 UTC
Last updated: 10/23/2026, 15:10:14 UTC
Views: 30
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