CVE-2026-62355 in TDengine
Summary
by MITRE • 07/15/2026
TDengine is an open source, time-series database optimized for Internet of Things devices. Prior to 3.4.1.15, a Data Reader admin_user on a TDengine Cloud DB instance could run create udf even though standard users should have read-only permissions for non-database objects and show dnodes and create user were denied. This issue is fixed in version 3.4.1.15.
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Analysis
by VulDB Data Team • 07/15/2026
This vulnerability represents a critical privilege escalation flaw in TDengine Cloud database instances that undermines the fundamental security model of the system. The issue affects versions prior to 3.4.1.15 where a specific user role known as Data Reader admin_user was able to execute unauthorized administrative commands despite having read-only permissions for non-database objects. This misconfiguration creates a significant security gap in the access control mechanism that should prevent standard users from performing privileged operations on database resources.
The technical flaw manifests through improper privilege validation within the TDengine Cloud implementation where the system fails to properly enforce role-based access controls for specific administrative functions. When the Data Reader admin_user attempts to execute create udf commands, the system incorrectly grants elevated privileges that should be restricted to administrators only. This bypass occurs because the access control logic does not adequately verify the user's actual role permissions before executing the command. The vulnerability is particularly concerning as it allows a user with read-only access to perform operations that are typically restricted to database administrators, effectively creating an unauthorized privilege escalation path.
The operational impact of this vulnerability extends beyond simple permission bypass and represents a serious threat to database integrity and security posture. An attacker who gains access to a Data Reader account could potentially exploit this flaw to create user accounts, execute user-defined functions, and gain access to the show dnodes command that reveals system information. This creates opportunities for privilege escalation attacks, data manipulation, and system reconnaissance that could compromise the entire database infrastructure. The vulnerability affects TDengine Cloud instances specifically, making it relevant to organizations using cloud-based time-series databases where security boundaries are critical.
The fix implemented in version 3.4.1.15 addresses this issue through proper access control enforcement mechanisms that validate user permissions before executing administrative commands. This remediation aligns with standard security practices for privilege management and demonstrates the importance of proper role-based access control implementation. The solution ensures that standard users cannot execute create udf operations or access administrative functions that should remain restricted to authorized administrators only. Organizations using TDengine Cloud should immediately upgrade to version 3.4.1.15 or later to mitigate this vulnerability.
From a cybersecurity perspective, this vulnerability maps to multiple ATT&CK tactics including privilege escalation and defense evasion where unauthorized users can bypass security controls to gain elevated privileges. The issue also reflects CWE-284 which describes improper access control in software systems, specifically the failure to properly enforce authorization checks for administrative operations. The vulnerability highlights the critical importance of implementing robust access control mechanisms in database systems, particularly in cloud environments where multiple user roles and permissions must be carefully managed to prevent unauthorized access and privilege escalation attacks.
This security flaw demonstrates the complexity of maintaining proper access controls in distributed database systems and underscores the need for regular security assessments and access control reviews. The vulnerability could potentially enable attackers to gain deeper insights into the database infrastructure and create persistent access points through user account creation capabilities. Organizations should implement comprehensive monitoring for unauthorized administrative command execution and maintain strict role-based access policies to prevent similar issues from occurring in their database environments.