CVE-2026-1850 is a vulnerability identified in MongoDB Server versions 8.0 and 8.2, categorized under CWE-770, which involves allocation of resources without proper limits or throttling. The issue arises within the MongoDB Query Planner component, where processing complex queries can lead to excessive memory consumption. This uncontrolled memory usage can cause the MongoDB server process to exhaust available memory, resulting in an out-of-memory (OOM) crash and subsequent denial of service. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, increasing its risk profile. The CVSS 4.0 base score is 7.1, reflecting high severity due to the potential for service disruption and ease of exploitation. No patches were linked at the time of publication, and no known exploits have been reported in the wild. The vulnerability impacts the availability of MongoDB services, which are widely used for data storage and management in various industries. Attackers could craft complex queries that trigger the excessive memory usage, causing server crashes and interrupting business operations. This flaw highlights the need for resource management controls within database query processing to prevent denial-of-service conditions.

For European organizations, the primary impact of CVE-2026-1850 is on the availability of MongoDB-based services. Organizations relying on affected MongoDB versions for critical applications, such as financial services, healthcare, government databases, and e-commerce platforms, may experience service outages or degraded performance due to OOM crashes triggered by malicious or malformed queries. This can lead to operational downtime, loss of customer trust, and potential financial losses. Additionally, repeated crashes could increase recovery times and administrative overhead. While confidentiality and integrity are not directly impacted, the disruption of service availability can have cascading effects on business continuity and compliance with data protection regulations such as GDPR. The vulnerability's remote exploitability without authentication increases the attack surface, making it easier for threat actors to launch denial-of-service attacks from external networks. European organizations with internet-facing MongoDB instances are particularly vulnerable.

1. Monitor MongoDB server memory usage closely and set up alerts for abnormal spikes that could indicate exploitation attempts. 2. Implement query complexity limits or restrict the use of resource-intensive query features to reduce the risk of triggering excessive memory consumption. 3. Apply resource quotas or cgroups at the operating system level to limit the maximum memory MongoDB can consume, preventing system-wide OOM conditions. 4. Restrict network access to MongoDB instances using firewalls and VPNs to limit exposure to untrusted networks and reduce the risk of remote exploitation. 5. Regularly update MongoDB to the latest patched versions once available from the vendor to address this vulnerability. 6. Employ Web Application Firewalls (WAFs) or database proxies that can detect and block suspicious query patterns indicative of exploitation attempts. 7. Conduct internal audits of query usage patterns and educate developers and DBAs on writing efficient queries that do not overload the query planner. 8. Consider deploying MongoDB in high-availability clusters with failover capabilities to minimize downtime in case of crashes.