CVE-2026-25612 is a vulnerability classified under CWE-412 (Unrestricted Externally Accessible Lock) affecting MongoDB Server versions 7.0, 8.0, and 8.2. The root cause lies in the internal locking mechanism of MongoDB, which uses an encoded representation of resources to determine lock acquisition. Due to this encoding, different collections may inadvertently map to the same internal lock resource, causing lock collisions. When such collisions occur, operations on these collections can block each other, leading to unavailability or denial of service conditions. The vulnerability does not require authentication or user interaction, and it can be triggered remotely over the network (AV:N, AC:L, PR:L, UI:N). The CVSS 4.0 vector indicates a high severity (7.1), primarily impacting availability (VA:H) without affecting confidentiality or integrity. Although no public exploits have been reported, the flaw could disrupt database operations, especially in environments with high concurrency or complex collection structures. MongoDB's internal lock management is critical for ensuring data consistency and performance; thus, this vulnerability poses a risk to service reliability. No patches are currently linked, so organizations should monitor vendor advisories closely. The issue highlights the importance of robust resource locking schemes in database engines to prevent unintended contention and service degradation.

For European organizations, the primary impact is on availability of MongoDB-based services. Enterprises relying on MongoDB for critical applications—such as financial services, e-commerce, healthcare, and public administration—may experience service interruptions or degraded performance due to lock collisions causing denial of service. This can lead to operational downtime, loss of productivity, and potential financial losses. Since MongoDB is widely used across Europe, especially in technology hubs and sectors with high data throughput, the risk of disruption is significant. The vulnerability does not directly compromise data confidentiality or integrity, but availability issues can indirectly affect business continuity and customer trust. Organizations with multi-tenant or high-concurrency database workloads are particularly vulnerable. Additionally, the lack of known exploits currently reduces immediate risk but does not eliminate the threat of future exploitation. The vulnerability may also complicate incident response and recovery efforts if lock contention leads to cascading failures or resource exhaustion.

1. Monitor MongoDB server logs and performance metrics closely to detect unusual lock contention or collection unavailability. 2. Limit the number of concurrent operations on collections known to cause lock collisions as a temporary workaround. 3. Review and optimize database schema design to minimize collection name collisions or resource encoding conflicts. 4. Implement rate limiting or throttling on database queries to reduce lock contention under high load. 5. Stay updated with MongoDB vendor advisories and apply patches promptly once released. 6. Consider deploying MongoDB in a high-availability cluster configuration to mitigate impact of localized unavailability. 7. Conduct thorough testing of database workloads in staging environments to identify potential lock collision scenarios before production deployment. 8. Engage with MongoDB support or security teams for guidance on interim fixes or configuration adjustments. 9. Use network segmentation and access controls to restrict exposure of MongoDB servers to trusted clients only, reducing risk of remote exploitation. 10. Prepare incident response plans specifically addressing database availability issues caused by locking conflicts.