CVE-2026-119179 in Node.js Driver
Summary
by MITRE • 11/03/2026
A flaw in the connection management layer of the MongoDB Node.js driver can leave a pooled network connection in the pool for reuse while data from an earlier operation is still outstanding on it. In applications that enable an optional client-side operation timeout, an unauthenticated party that can send ordinary requests to the application may cause database replies to be paired with the wrong requests. This may result in unintended disclosure of other users' records, incorrect operation results being returned, and failures of legitimate requests.
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Analysis
by VulDB Data Team • 11/03/2026
The vulnerability identified within the MongoDB Node.js driver stems from a critical flaw in its connection management layer, specifically affecting how pooled network connections are handled during concurrent operations. In high-concurrency environments where database drivers maintain a pool of reusable TCP connections to optimize performance and reduce latency, the integrity of request-response pairing is paramount. The core technical issue arises when a connection that has been returned to the pool for reuse still contains outstanding data from a previous operation that was not fully consumed or cleared before being marked as available. This state inconsistency creates a race condition where subsequent requests assigned to this same physical socket may inadvertently receive responses intended for earlier, pending operations rather than their own specific queries.
This flaw is particularly exploitable in applications that utilize client-side operation timeouts. When such timeouts are enabled, the driver may cancel or discard an ongoing request after a specified duration if it has not completed within the allotted time. However, due to the connection management defect, the underlying socket remains active and potentially holds residual data from the timed-out operation. If this compromised connection is immediately reassigned to a new, legitimate user request, there is no mechanism to ensure that incoming network packets are correctly matched with their corresponding outgoing requests. Consequently, an unauthenticated attacker who can send ordinary HTTP or API requests to the application interface may trigger scenarios where database replies intended for one context are delivered to another unrelated context.
The operational impact of this vulnerability is severe and multifaceted, primarily centering on data integrity and confidentiality breaches. The most critical consequence is the unintended disclosure of sensitive information belonging to other users. Because responses can be misrouted, an attacker might receive database records that were intended for a different session or user ID, effectively bypassing authentication and authorization controls at the application layer by exploiting lower-level network protocol ambiguities. Beyond data leakage, this flaw leads to incorrect operation results being returned to legitimate clients, which can cause logical errors in business processes, such as updating wrong records or retrieving stale data. Furthermore, it causes failures of legitimate requests, leading to service degradation and potential denial-of-service conditions for valid users who experience corrupted responses or connection resets due to the state mismatch.
From a classification perspective, this vulnerability aligns with CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization, as the issue involves shared network resources (the pooled connections) being accessed without proper synchronization of their internal states relative to pending I/O operations. It also relates closely to CWE-918: Server-Side Request Forgery (SSRF), although in this specific context, it manifests more as a response injection or misrouting flaw rather than traditional SSRF where the server makes requests on behalf of an attacker. In terms of the MITRE ATT&CK framework, this behavior facilitates Data Exfiltration over Application Layer Protocols and can be categorized under techniques that exploit trust relationships within software components to bypass security controls.
Mitigation strategies must address both immediate remediation and long-term architectural resilience. The primary solution is for application developers to upgrade their MongoDB Node.js driver dependencies to versions where the connection management logic has been patched to ensure strict isolation of pending data before a socket is returned to the pool. This typically involves implementing rigorous state checks that verify all previous operations on a connection have fully completed and their responses consumed before allowing reuse. Additionally, applications should consider disabling client-side operation timeouts if they are not strictly necessary for performance optimization, as this feature exacerbates the race condition by creating abrupt terminations of pending requests while leaving residual data in the socket buffer. For environments where high concurrency is essential, implementing a more robust connection pooling strategy that validates response headers or sequence numbers can provide an additional layer of defense against misrouted packets. Regular security audits focusing on network I/O handling and concurrent resource management are also recommended to identify similar synchronization flaws in other parts of the application stack.