A heap-based buffer overflow vulnerability in Microsoft SQL Server, designated CVE-2026-67380, allows an authenticated attacker to achieve remote code execution on the target database server.

This vulnerability is a heap-based buffer overflow (CWE-122) triggered by improper memory management within the SQL Server engine. The attack requires an authenticated user to send a specially crafted request over the network to the database service.

The ability for an authenticated attacker to execute arbitrary code presents a critical risk to data confidentiality, integrity, and availability. Successful exploitation could lead to full database compromise, unauthorized data exfiltration, or the installation of persistent malicious backdoors. Given the CVSS score of 8.8, this vulnerability is categorized as High severity and requires immediate prioritization to prevent unauthorized escalation and system takeover.

Immediate Action: Apply the vendor-provided security patches corresponding to the specific SQL Server version and release branch identified in the fixed versions list.

Proactive Monitoring: Review SQL Server error logs for unusual service crashes or memory access violations that may indicate exploitation attempts.

Compensating Controls: Restrict network access to the SQL Server instance to only known, authorized application servers and administrative workstations to limit the pool of potential attackers.

Public Exploit Available: No (Exploit_available: false).

Organizations should treat this vulnerability with high urgency due to the potential for full system compromise. Administrators must verify their current SQL Server build numbers against the fixed versions provided by Microsoft and schedule maintenance windows to apply the necessary security updates as soon as possible.