Microsoft SQL Server: Heap-based buffer overflow allows remote code execution
Summary
Microsoft SQL Server contains a heap-based buffer overflow (CWE-122) that allows an authorized attacker to execute code over a network. The attacker needs valid, low-privilege credentials on the database, so the main exposure is SQL Server instances that are reachable from untrusted networks or used by many accounts. The NVD analysis is still pending and the vendor advisory could not be verified for this CVE ID.
Affected
- Microsoft SQL Server 2017 (GDR): 14.0.0 to before 14.0.2150.2
- Microsoft SQL Server 2017 for x64-based Systems (CU31): 14.0.3006.16 to before 14.0.3570.2
- Microsoft SQL Server 2019 (GDR): 15.0.0 to before 15.0.2210.4
- Microsoft SQL Server 2019 for x64-based Systems (CU32): 15.0.4003.23 to before 15.0.4510.2
- Microsoft SQL Server 2022 (GDR): 16.0.0 to before 16.0.1220.3
- Microsoft SQL Server 2022 for x64-based Systems (CU27): 16.0.4003.1 to before 16.0.4315.2
- Microsoft SQL Server 2025 CU10: 17.0.4006.0 to before 17.0.5045.3
- Microsoft SQL Server 2025 for x64-based Systems (GDR): 17.0.1050.2 to before 17.0.1155.3
Fixed in
Unknown. The fixed builds for CVE-2026-67637 could not be confirmed from the vendor advisory.
Workaround
Unknown. No workaround or mitigation was found for this CVE.
Exploitation
Unknown. No in-the-wild exploitation, public proof of concept or CISA KEV entry was found for this CVE.
Our recommendation
- Check the MSRC advisory for CVE-2026-67637 directly to confirm affected and fixed builds.
- Inventory all SQL Server instances and versions, and confirm none are reachable from the internet.
- Review database accounts and remove unused or unnecessary logins.
- Apply the cumulative security update for each installed branch once the fixed build is confirmed.
- Re-check NVD and CISA KEV after the NVD analysis is complete.
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC Security Update Guide: CVE-2026-67637 msrc.microsoft.com
- CVE Record CVE-2025-67637 (CVE.org) www.cve.org
- MSRC advisory for sibling CVE-2026-67639 msrc.microsoft.com
- SQL Server 2025 GDR September 2026 (KB5122770) support.microsoft.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 10 Nov 2026, 21:02.
Original description (NVD)
Heap-based buffer overflow in SQL Server allows an authorized attacker to execute code over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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