CVE-2026-82062 in MongoDB
Summary
by MITRE • 09/08/2026
A security issue in MongoDB Server allows an authenticated user with elevated internal privileges to bypass a disabled feature gate in the applyOps command by specifying an internal replication mode value that was not intended to be client-selectable. This bypass enables execution of container operations that are disabled by default in production configurations, allowing direct storage-engine writes to arbitrary internal storage tables. The authorization check for these operations validates only the operation's namespace, not the actual storage target, enabling writes to unrelated internal metadata or other collections' data.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability described represents a critical privilege escalation and integrity compromise within MongoDB Server, specifically affecting versions where the applyOps command is accessible to authenticated users with elevated internal privileges. This flaw centers on an authorization logic error that allows such users to bypass security controls designed to restrict certain high-impact operations in production environments. Specifically, the issue involves the manipulation of a disabled feature gate through the specification of an internal replication mode value within the applyOps command. These internal modes are not intended for client selection and serve as safeguards to prevent direct interaction with low-level storage mechanisms that could destabilize or compromise the database integrity if misused by unauthorized actors.
The core technical flaw lies in how MongoDB validates authorization checks for operations executed via applyOps when specific replication modes are requested. The system performs an authorization check that verifies only the namespace of the operation, which refers to the logical collection or table being targeted. However, it fails to validate the actual storage target where the data will be written at the engine level. This discrepancy creates a significant gap in security enforcement because the validation logic does not account for whether the underlying storage-engine write is directed toward an allowed destination or an arbitrary internal storage table. Consequently, an attacker with sufficient privileges can exploit this mismatch to execute container operations that are explicitly disabled by default in standard production configurations.
The operational impact of this vulnerability is severe, as it enables direct writes to arbitrary internal storage tables and metadata structures. By bypassing the intended restrictions on replication modes, a malicious actor can manipulate internal MongoDB data structures directly through the storage engine interface rather than through the normal query or update pathways. This capability allows for the modification of unrelated internal metadata or the corruption of other collections' data without triggering standard audit logs or security alerts associated with typical write operations. The ability to bypass disabled feature gates effectively neutralizes a key defense-in-depth measure, allowing privileged users to perform actions that should be restricted even if they possess high-level access rights.
From an industry standards perspective, this vulnerability aligns closely with CWE-269 Improper Privilege Management and CWE-732 Incorrect Permission Assignment for Critical Resource. The failure to validate the actual storage target against authorized permissions constitutes a classic permission bypass scenario where the system trusts input parameters that should be strictly controlled by internal logic. In terms of adversarial tactics, this behavior is consistent with ATT&CK technique T1068 Exploitation for Privilege Escalation and potentially T1562 Impair Defenses if used to disable security features or alter audit configurations. The exploitation path leverages legitimate administrative commands but abuses their internal processing logic to achieve unauthorized outcomes, highlighting the risks associated with exposing powerful operational interfaces to users who may have elevated but not absolute root-level access.
Mitigation strategies must focus on tightening authorization checks within the applyOps command implementation. Developers should ensure that any operation involving internal replication modes or direct storage-engine interactions undergoes rigorous validation of both the logical namespace and the physical storage target against a comprehensive allowlist of permitted operations for each privilege level. Additionally, feature gates controlling access to these low-level mechanisms should be enforced at multiple layers, including the command parser stage, rather than relying solely on post-parsing authorization checks that may overlook internal state modifications. For administrators currently running vulnerable versions, it is crucial to audit user privileges and restrict applyOps permissions only to users who absolutely require them for critical maintenance tasks, while monitoring logs for any unusual replication mode selections or unexpected writes to system collections.