CVE-2026-82076 in MongoDB
Summary
by MITRE • 09/08/2026
An integer overflow in the query planning component of MongoDB Server can allow an authenticated user with ordinary database-level read/write privileges to bypass an internal resource limit. Submitting a specially crafted query causes the server to consume memory without bound during query planning, and the resulting exhaustion terminates the server process. This may result in a denial of service affecting all databases served by the affected node.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified involves a critical integer overflow within the query planning subsystem of MongoDB Server. This flaw allows an authenticated user possessing standard database-level read and write privileges to exploit internal resource management mechanisms, specifically bypassing limits designed to prevent excessive memory consumption during query execution preparation. The core technical issue stems from improper handling of arithmetic operations when calculating buffer sizes or array bounds for data structures used in the planning phase. When a specially crafted query is submitted, the integer overflow causes the system to allocate significantly more memory than intended, leading to unbounded memory growth as the server attempts to process the malformed request parameters.
From an operational perspective, this vulnerability poses a severe risk of denial of service against MongoDB instances. As the server consumes memory without bound during the query planning stage, it eventually exhausts available system resources or triggers out-of-memory conditions that force the termination of the mongod process. This crash affects all databases hosted on the affected node, not just the targeted database associated with the attacking user's credentials. Consequently, legitimate users and applications relying on the MongoDB instance experience a complete loss of service until the server is manually restarted by an administrator or automated recovery systems intervene.
This vulnerability aligns with Common Weakness Enumeration (CWE) category CWE-190, which describes integer overflow or wraparound errors that can lead to unexpected behavior in software logic. In terms of attack classification under the MITRE ATT&CK framework, this exploit falls under T1498 Network Denial of Service, specifically reflecting techniques where an attacker leverages resource exhaustion through malformed inputs rather than direct network flooding. The fact that authentication is required but only standard privileges are needed highlights a significant privilege escalation aspect in terms of impact scope versus access level granted.
Mitigation strategies primarily involve upgrading to patched versions of MongoDB Server where the integer overflow has been corrected and proper bounds checking is implemented during query planning. Organizations should also enforce strict input validation on application layers connecting to the database, although this vulnerability specifically targets server-side processing logic that client-side controls cannot fully mitigate. Additionally, implementing resource limits at the operating system level, such as cgroups in Linux environments or memory quotas for the mongod process, can provide a secondary layer of defense by preventing any single process from consuming all available host memory and crashing the entire node. Regular monitoring of database server health metrics, particularly memory usage trends during peak query loads, is recommended to detect anomalous behavior indicative of such exploitation attempts before they result in service disruption.