CVE-2026-101771 in MySQL Server
Summary
by MITRE • 10/21/2026
Vulnerability in the MySQL Server, MySQL Cluster product of Oracle MySQL (component: Client programs). Supported versions that are affected are MySQL Server: 8.4.0-8.4.12, 9.7.0-9.7.3, 26.7.0-26.7.1; MySQL Cluster: 8.0.0-8.0.49, 8.4.0-8.4.12, 9.7.0-9.7.3 and 26.7.0-26.7.1. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise MySQL Server, MySQL Cluster. Successful attacks of this vulnerability can result in takeover of MySQL Server, MySQL Cluster. CVSS 3.1 Base Score 8.1 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).
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Analysis
by VulDB Data Team • 10/21/2026
The identified vulnerability resides within the client programs component of Oracle MySQL Server and MySQL Cluster products, affecting a broad range of supported versions including MySQL Server 8.4 through 8.4.12, 9.7 through 9.7.3, and 26.7 through 26.7.1, as well as corresponding releases in the MySQL Cluster series from version 8.0 up to 8.0.49 and the newer 8.4, 9.7, and 26.7 branches. This flaw represents a critical security deficiency that permits an unauthenticated attacker with network access via multiple protocols to compromise the integrity of the database infrastructure. The severity is quantified by a CVSS v3.1 Base Score of 8.1, indicating a High risk level due to significant impacts on confidentiality, integrity, and availability. The specific vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H) reveals that while the attack requires high complexity, it does not necessitate user interaction or prior authentication, allowing for remote exploitation over a network connection with full system takeover potential upon success.
From a technical perspective, this vulnerability likely stems from improper validation of input data within the client-side processing logic before execution by the server engine. Although classified as difficult to exploit due to high attack complexity, which may involve specific timing conditions or complex payload construction, the absence of authentication requirements makes it particularly dangerous in environments where database ports are exposed to untrusted networks. The flaw allows an attacker to execute arbitrary code or manipulate internal states within the MySQL process context, leading to a complete compromise of the server environment. This aligns with CWE-20 Improper Input Validation and potentially CWE-78 OS Command Injection if the vulnerability involves shell metacharacter interpretation in client tools that pass data directly to system-level operations. The high complexity suggests that successful exploitation might require precise manipulation of protocol states or specific edge cases in how multi-threaded connections are handled, but once triggered, it bypasses standard security controls designed for unauthenticated access scenarios.
The operational impact of this vulnerability is severe, as a successful exploit results in the complete takeover of the MySQL Server or Cluster node. This means an attacker gains the same privileges as the database service account, which often runs with elevated permissions to manage files and network sockets on the host system. Such compromise enables unauthorized access to sensitive data stored within the databases, violating confidentiality requirements under standards like GDPR or HIPAA if applicable. Furthermore, the ability to modify data undermines integrity guarantees essential for financial transactions, healthcare records, or critical infrastructure monitoring. The availability impact is equally concerning, as attackers could disrupt database services through denial-of-service techniques facilitated by the same code path that allows remote execution, effectively rendering mission-critical applications inaccessible. This triad of impacts reflects a catastrophic failure in security boundaries between network-facing components and internal system resources.
In terms of threat modeling, this vulnerability maps to MITRE ATT&CK technique T1059 Command and Scripting Interpreter if the exploit involves executing scripts via client tools, or potentially T1213 Data from Information Repositories for unauthorized data exfiltration following initial access. The network-based nature places it within the Initial Access or Execution tactics depending on whether the primary goal is persistence or immediate control. Security teams must recognize that even high-complexity vulnerabilities can be weaponized by automated tools in targeted attacks where time and resources are not limiting factors. The broad version range affected indicates a systemic issue in shared codebases across different product lines, suggesting that patches may need to be applied consistently across heterogeneous database environments to prevent lateral movement or exploitation of less hardened nodes within the same network segment.
Mitigation strategies must prioritize immediate patching for all supported versions listed above. Organizations should apply the latest security updates provided by Oracle promptly to close the input validation gaps in client programs. In scenarios where patching is not immediately feasible, strict network segmentation and firewall rules restricting access to MySQL ports (typically 3306) to only trusted application servers or administrative workstations can significantly reduce the attack surface. Additionally, enabling TLS encryption for all connections ensures that even if an attacker intercepts traffic, they cannot easily analyze protocol behavior to craft complex exploits requiring high complexity. Implementing robust intrusion detection systems tuned for anomalous database query patterns may also help detect attempted exploitation activities before successful compromise occurs. Regular audits of client tool configurations and disabling unnecessary features or protocols can further harden the environment against such remote code execution attempts.