CVE-2026-25612 Overview
A resource locking vulnerability exists in the MongoDB server's internal locking mechanism. The server uses an internal encoding scheme for resources when determining which locks to acquire. Due to improper resource identification within this encoding, collections may inadvertently collide with one another in the internal representation, causing unavailability between them due to conflicting locks. This vulnerability can lead to denial of service conditions affecting database availability.
Critical Impact
Authenticated attackers with network access can trigger lock collisions between MongoDB collections, causing resource unavailability and denial of service conditions that impact database operations.
Affected Products
- MongoDB Server (specific versions not disclosed in advisory)
Discovery Timeline
- 2026-02-10 - CVE-2026-25612 published to NVD
- 2026-02-10 - Last updated in NVD database
Technical Details for CVE-2026-25612
Vulnerability Analysis
This vulnerability falls under CWE-412 (Unrestricted Externally Accessible Lock), which describes scenarios where improper lock handling can lead to resource availability issues. The MongoDB server's internal locking mechanism relies on an encoding scheme to identify resources for lock acquisition. When collections are processed through this encoding, hash collisions or encoding conflicts can occur, causing distinct collections to be treated as the same resource from a locking perspective.
The vulnerability requires low privileges to exploit over a network connection with no user interaction needed. While it does not impact confidentiality or integrity, it poses a significant threat to system availability. An attacker who can interact with the database could potentially craft operations that trigger these lock collisions, causing legitimate operations on unrelated collections to block or fail.
Root Cause
The root cause lies in the internal resource encoding algorithm used by MongoDB's locking subsystem. When the server needs to acquire locks for collection operations, it generates an internal representation of the resource to determine the appropriate lock. The encoding scheme does not provide sufficient uniqueness guarantees, allowing distinct collections to produce colliding internal representations. This collision causes the locking mechanism to treat separate collections as the same resource, leading to unintended lock conflicts between operations that should be independent.
Attack Vector
The attack vector is network-based, requiring authentication with low privileges. An attacker with basic database access could exploit this vulnerability by:
- Identifying or creating collections that produce colliding internal lock representations
- Initiating operations on these collections that acquire conflicting locks
- Causing legitimate operations on one collection to be blocked by locks held on another collection
- Repeatedly triggering these collisions to maintain a denial of service condition
The vulnerability does not require any user interaction and can be exploited with standard database operations once the collision conditions are understood.
Detection Methods for CVE-2026-25612
Indicators of Compromise
- Unexpected lock wait timeouts or deadlock errors in MongoDB logs
- Collections experiencing availability issues without direct correlation to their workload
- Unusual patterns of lock acquisition failures in database metrics
- Operations on distinct collections blocking each other unexpectedly
Detection Strategies
- Monitor MongoDB server logs for abnormal lock contention patterns between unrelated collections
- Implement alerting on increased lock wait times and lock timeout errors
- Track collection-level operation latencies to identify unexplained blocking behavior
- Review database slow query logs for operations blocked by locks on different collections
Monitoring Recommendations
- Enable verbose logging for MongoDB's lock manager to capture detailed lock acquisition events
- Configure monitoring dashboards to display lock contention metrics by collection
- Set up alerts for sudden increases in lock-related errors or timeouts
- Implement baseline monitoring of typical lock behavior to detect anomalies
How to Mitigate CVE-2026-25612
Immediate Actions Required
- Review MongoDB security advisories for patched versions addressing this vulnerability
- Audit database access controls to ensure only trusted users have collection access
- Monitor for unusual lock contention patterns that may indicate exploitation attempts
- Consider isolating critical collections to separate MongoDB instances if possible
Patch Information
MongoDB has acknowledged this issue through their Jira tracking system. Administrators should consult the official MongoDB security resources and the referenced Jira issues for patch availability and specific version information:
Upgrade to the latest patched version of MongoDB server once available to fully remediate this vulnerability.
Workarounds
- Implement rate limiting on database operations to reduce the likelihood of lock collision exploitation
- Review and minimize the privileges granted to database users where possible
- Consider implementing application-level locking for critical operations as an additional safeguard
- Deploy network segmentation to limit which systems can connect to MongoDB instances
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
