CVE-2026-54117 in SQL Server
Summary
by MITRE • 07/14/2026
Deserialization of untrusted data in SQL Server allows an authorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical deserialization flaw that exploits the trust relationship between authorized users and sql server systems. When sql server processes untrusted data through deserialization mechanisms, it creates an attack vector where authenticated users can manipulate serialized objects to execute arbitrary code remotely. The flaw typically occurs when the database engine accepts serialized data from external sources without proper validation or sanitization, allowing attackers to craft malicious payloads that bypass normal security controls. This vulnerability directly aligns with cwe-502 which specifically addresses deserialization of untrusted data as a primary weakness in software systems.
The technical exploitation involves an attacker leveraging their authorized access to submit specially crafted serialized objects that contain malicious code or commands. These objects are then deserialized by sql server processes, executing the embedded payload within the database environment. The remote execution capability means attackers can operate from external network positions while maintaining their authenticated session, making detection more challenging. This attack pattern falls under the broader category of privilege escalation and remote code execution threats that have been documented in various security frameworks including the mitre att&ck matrix where it would map to techniques involving command and control communications and remote service execution.
The operational impact of this vulnerability extends beyond simple code execution, as successful exploitation can lead to complete database compromise, data exfiltration, and potential lateral movement within network environments. Attackers can use this capability to escalate privileges, install backdoors, or manipulate database content without raising immediate detection flags since the initial access is authenticated. Organizations may experience significant data loss, compliance violations, and operational disruption when such vulnerabilities are exploited. The risk is particularly elevated in environments where sql server instances are accessible from external networks or where users maintain broad database permissions that exceed their operational requirements.
Effective mitigations must address both the immediate deserialization risks and broader security posture issues. Organizations should implement strict input validation and sanitization for all data entering sql server systems, particularly when dealing with serialized objects from external sources. Regular security updates and patches should be applied to eliminate known vulnerabilities in sql server components that may facilitate such attacks. Network segmentation and access controls should limit direct external access to database servers while implementing robust monitoring for unusual deserialization activities or command execution patterns. Additionally, principle of least privilege enforcement ensures that users only receive the minimum permissions necessary for their roles, reducing potential damage from successful exploitation attempts. Security awareness training for database administrators and developers can help prevent introduction of vulnerable deserialization code into production systems, while regular vulnerability assessments should identify and remediate any remaining deserialization weaknesses in sql server configurations.