CVE-2026-67631: CWE-122: Heap-based Buffer Overflow in Microsoft Microsoft SQL Server 2017 (CU 31)
Description
CVE-2026-67631 is a critical heap-based buffer overflow vulnerability in Microsoft SQL Server 2017 (CU 31) that allows an unauthorized attacker to execute code remotely over a network. The vulnerability affects multiple versions of SQL Server 2017, 2019, 2022, and 2024 builds prior to specific fixed versions. An official fix is available from Microsoft.
CVSS v3.1
Score 9.8critical
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-122 (heap-based buffer overflow), exists in Microsoft SQL Server 2017 (CU 31) and later versions up to certain builds in SQL Server 2017, 2019, 2022, and 2024. It allows an unauthenticated attacker to remotely execute arbitrary code by exploiting a heap overflow condition. The CVSS v3.1 base score is 9.8, indicating critical severity with network attack vector, no privileges required, and no user interaction needed. Microsoft has published an official fix to address this vulnerability.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to execute arbitrary code on the affected SQL Server instance remotely without authentication. This can lead to full compromise of the server, including confidentiality, integrity, and availability impacts.
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-2026-67631 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-07-29T22:49:19.796Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-67631","vendor":"Microsoft"}]
Threat ID: 6aa044cdacd9273b49fa7ba0
Added to database: 09/08/2026, 17:24:29 UTC
Last enriched: 10/16/2026, 20:51:46 UTC
Last updated: 10/23/2026, 15:10:14 UTC
Views: 24
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