Microsoft SQL Server: Heap-based buffer overflow allows remote code execution
Summary
A heap-based buffer overflow in Microsoft SQL Server allows an authorized attacker with low privileges to execute code over the network. The CVSS vector (AV:N/AC:L/PR:L/UI:N) indicates that no user interaction is needed, but this vector has not been verified against the vendor advisory. Successful exploitation would give the attacker high impact on confidentiality, integrity and availability of the database server.
Affected
- Microsoft SQL Server 2017, 2019, 2022 and 2025 (affected build ranges per CNA record, see below)
- SQL Server 2017 (GDR): 14.0.0 to < 14.0.2150.2
- SQL Server 2017 for x64-based Systems (CU31): 14.0.3006.16 to < 14.0.3570.2
- SQL Server 2019 (GDR): 15.0.0 to < 15.0.2210.4
- SQL Server 2019 for x64-based Systems (CU32): 15.0.4003.23 to < 15.0.4510.2
- SQL Server 2022 (GDR): 16.0.0 to < 16.0.1220.3
- SQL Server 2022 for x64-based Systems (CU27): 16.0.4003.1 to < 16.0.4315.2
- SQL Server 2025 CU10: 17.0.4006.0 to < 17.0.5045.3
- SQL Server 2025 for x64-based Systems (GDR): 17.0.1050.2 to < 17.0.1155.3
Fixed in
Unknown. The fixed builds are not confirmed by a source I could verify; check the MSRC page for the fixed versions.
Workaround
Unknown.
Exploitation
- No evidence of exploitation in the wild found.
- No public proof of concept found.
- The CVSS vector is taken from the supplied input and is not verified.
Our recommendation
- Open the MSRC advisory and record the affected and fixed builds.
- Inventory all SQL Server instances (version, build, network exposure, login accounts) and remove internet exposure where not needed.
- Apply the cumulative update containing the fix once confirmed.
- Monitor NVD, CISA KEV and the vendor page over the coming days.
- Priority: moderate by default; raise to high if SQL Server is reachable from the internet, partner networks or shared hosting.
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-67391 msrc.microsoft.com
- Microsoft SQL Server 2022 CU26 GDR (September 2026) support.microsoft.com
- Microsoft SQL Server 2025 CU8 (September 2026) support.microsoft.com
- Microsoft Security Update Guide: CVE-2026-67639 (sibling CVE, context only) msrc.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, 21:03.
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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