CVE-2026-18694 in MongoDB
Summary
by MITRE • 08/11/2026
An issue in MongoDB Server's geospatial query processing could allow an authenticated user with write privileges to cause certain malformed geometry data to be stored and later processed without proper validation. Subsequent queries against this data could then result in the server accessing memory outside its intended bounds. This could result in a server crash (denial of service) and may expose a limited amount of server process memory.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability exists within mongodb server's geospatial query processing functionality and represents a critical security flaw that can be exploited by authenticated users possessing write privileges. The issue stems from inadequate validation of malformed geometry data during the storage phase, allowing maliciously crafted spatial data to be persisted in the database system. When subsequent queries attempt to process this corrupted data, the server experiences unauthorized memory access patterns that extend beyond allocated boundaries. This fundamental flaw in input validation creates a pathway for both denial of service attacks and potential information disclosure through memory exposure. The vulnerability specifically targets the geospatial indexing and querying mechanisms that are commonly used in applications requiring location-based services, mapping functionalities, or spatial analytics. Attackers can leverage this weakness by injecting malformed geometric objects through write operations, which then remain undetected until queried later. The memory access violations typically manifest as server crashes or unexpected termination of database processes, effectively disrupting legitimate service availability for authorized users.
The technical implementation of this vulnerability aligns with common software security principles where input validation failures lead to memory corruption issues. This flaw can be categorized under cwe-129 which describes improper validation of array indices and cwe-119 which covers weaknesses in memory management. The attack vector specifically follows the pattern described in mitre att&ck technique t1499 which involves creating or manipulating data to cause system instability or denial of service. The exploitation requires only write privileges rather than elevated administrative access, making it particularly dangerous for environments where multiple users have database write permissions. When the malformed geometry data is processed during spatial queries, the server's memory management routines fail to properly handle boundary checks, leading to buffer overreads or overwrites that can compromise system stability and potentially expose sensitive process memory contents.
The operational impact of this vulnerability extends beyond simple service disruption to encompass potential data integrity concerns and information leakage risks. Organizations utilizing mongodb for geospatial applications face significant exposure since the attack requires minimal privileges and can be executed through normal database write operations. The vulnerability affects systems where spatial data is frequently stored and queried, particularly those supporting mapping services, logistics tracking, or location-based social applications. Server crashes resulting from this issue can cause extended downtime for critical business applications that depend on geospatial functionality. Additionally, the potential memory exposure could reveal sensitive information such as database connection details, user credentials, or internal system structures depending on what data resides in the accessible memory regions. The vulnerability's persistence means that once exploited, the malicious data remains in the database until manually removed or the server is restarted, creating ongoing risk for affected systems.
Mitigation strategies should focus on immediate patch application and enhanced input validation measures within mongodb deployments. Organizations must prioritize updating their mongodb instances to versions that address this specific memory access vulnerability through proper geometry data validation. Database administrators should implement strict spatial data validation routines at the application layer before storing geospatial information, using library functions or custom validation logic to ensure all geometries conform to expected formats and boundaries. Network segmentation and privilege reduction practices can help limit the potential impact by restricting write access to geospatial data to only essential administrative users. Monitoring systems should be enhanced to detect unusual query patterns or memory access anomalies that might indicate exploitation attempts. Additionally, implementing database audit trails for geospatial operations can help identify suspicious activities and provide forensic evidence if compromise occurs. Regular security assessments of mongodb configurations and geospatial functionality usage should be conducted to identify and remediate similar validation gaps that could lead to additional vulnerabilities in the system's spatial processing capabilities.