CVE-2026-13064 in MongoDB
Summary
by MITRE • 07/22/2026
Certain query operations involving deeply nested $jsonSchema constructs can trigger disproportionate CPU consumption in affected MongoDB deployments, potentially leading to resource exhaustion. The resulting CPU-bound operation cannot be interrupted through standard administrative controls.
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Analysis
by VulDB Data Team • 07/22/2026
This vulnerability represents a critical performance degradation issue within MongoDB's schema validation mechanisms that specifically impacts deployments utilizing complex $jsonSchema definitions. The flaw manifests when query operations process deeply nested JSON schema constructs, causing the database engine to consume excessive computational resources in proportion to the schema complexity rather than maintaining scalable performance characteristics. This behavior creates a denial of service condition where legitimate database operations become severely degraded or unresponsive due to the disproportionate CPU utilization patterns inherent in the schema validation processing pipeline.
The technical root cause stems from how MongoDB handles recursive schema validation during query execution, particularly when dealing with deeply nested object structures within $jsonSchema definitions. The system fails to implement proper resource limiting or early termination mechanisms during schema validation phases, allowing a single complex query to consume CPU cycles exponentially relative to the nesting depth. This issue specifically affects the database's internal schema validation engine which operates outside normal query interruption controls, making it impossible for administrators to terminate problematic operations through standard administrative interfaces or timeout configurations. The vulnerability demonstrates characteristics consistent with CWE-400 - Uncontrolled Resource Consumption and aligns with ATT&CK technique T1496 - Resource Exhaustion where adversaries can leverage such weaknesses to exhaust system resources.
The operational impact of this vulnerability extends beyond simple performance degradation to potentially compromise entire database availability. Affected deployments may experience complete service unresponsiveness where legitimate queries time out or fail to complete, while the system remains stuck processing the malformed schema validation requests. Administrators cannot employ standard resource management techniques such as query timeouts, connection limits, or operation interruption commands to resolve the situation once triggered. This creates a particularly dangerous scenario for production environments where database availability is critical to business operations. The vulnerability affects MongoDB versions that support $jsonSchema validation features and can be exploited through any query operation that involves complex nested schema constructs, making it difficult to predict or prevent in environments with dynamic schema definitions.
Mitigation strategies should focus on implementing comprehensive schema design practices that avoid excessive nesting levels within $jsonSchema definitions, establishing proper resource monitoring and alerting mechanisms to detect abnormal CPU consumption patterns, and implementing database-level resource limits through configuration parameters. Organizations should consider upgrading to patched versions of MongoDB where appropriate, implementing query validation layers to sanitize input schemas before processing, and establishing automated failover procedures to maintain service availability during exploitation attempts. The vulnerability highlights the importance of proper schema design practices and demonstrates why complex validation mechanisms require careful consideration of resource implications in production environments.