CVE-2026-54116 in SQL Server
Summary
by MITRE • 07/14/2026
Access of resource using incompatible type ('type confusion') in SQL Server allows an authorized attacker to disclose information over a network.
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Analysis
by VulDB Data Team • 07/15/2026
Type confusion vulnerabilities represent a critical class of software flaws that occur when a program uses a resource in an manner inconsistent with its declared type, creating opportunities for unauthorized access and data disclosure. In the context of Microsoft SQL Server, this specific vulnerability manifests when legitimate authenticated users exploit improper type handling within database operations to gain access to information they should not be able to retrieve. The flaw typically arises from insufficient type checking mechanisms during query processing or result set handling where the system fails to properly validate the expected data types before performing operations. This allows an attacker who has already established authentication credentials to manipulate database interactions in ways that bypass normal access controls and expose sensitive information through network communications.
The technical exploitation of this vulnerability involves leveraging SQL Server's internal type handling mechanisms to force the system into processing data as incorrect types, which can lead to memory corruption or unexpected behavior that reveals internal database structures. When an attacker successfully triggers this condition, they can potentially extract metadata about database schemas, user privileges, or even sensitive data values through crafted queries that exploit the type confusion. The vulnerability is particularly dangerous because it requires only authentication credentials rather than administrative privileges, making it accessible to users with legitimate database access who may have limited permissions. This creates a significant risk for organizations where privilege escalation occurs through legitimate business processes or compromised user accounts.
From an operational impact perspective, this vulnerability can result in substantial data exposure and potential compliance violations, especially in environments handling sensitive information such as financial records, personal identification data, or intellectual property. The network-based nature of the attack means that even users with restricted database access can potentially exfiltrate information without requiring physical access to server hardware or elevated administrative privileges. Security teams must consider the implications for their monitoring capabilities since this type of attack often appears as normal database activity, making detection more challenging. Organizations may face regulatory scrutiny and potential legal consequences if sensitive data is compromised through such vulnerabilities, particularly when they involve customer information or proprietary business data.
Mitigation strategies should focus on implementing comprehensive input validation controls and ensuring proper type checking mechanisms are in place throughout SQL Server operations. Microsoft recommends applying the latest security patches and updates that address the specific type confusion issues within database processing components. Organizations should also implement network segmentation to limit access to database servers, enforce strict access controls through role-based permissions, and maintain detailed monitoring of database activities for unusual query patterns. Additional defensive measures include implementing database activity monitoring tools that can detect anomalous behavior indicative of exploitation attempts, regularly reviewing and testing access controls, and conducting thorough security assessments of database configurations. The vulnerability aligns with CWE-457: Use of Uninitialized Variable and ATT&CK technique T1213.002: Data from Information Repositories, emphasizing the need for proper resource management and access control enforcement in database environments.