CVE-2026-107324 in Go Driver
Summary
by MITRE • 10/08/2026
An integer overflow in BSON value-length handling in the MongoDB Go Driver can cause a runtime panic when an application validates or accesses a malformed BSON document. An unauthenticated actor who can supply BSON bytes to an affected application may terminate an unprotected application process, causing a denial of service. The driver's server-monitoring path contains panic recovery and is limited to server-selection failure.
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Analysis
by VulDB Data Team • 10/08/2026
The MongoDB Go Driver exhibits a critical integer overflow vulnerability within its handling of BSON value lengths, specifically affecting the parsing logic for malformed documents. This flaw arises when the driver processes input data where the declared length fields are crafted to exceed the maximum capacity of the underlying integer types used by the language runtime. When an application utilizes this driver to validate or access such a maliciously constructed BSON document, the arithmetic operation calculating the buffer size or offset wraps around due to the overflow condition. This miscalculation leads to invalid memory allocation requests or out-of-bounds array indexing operations within the Go runtime environment. Consequently, instead of gracefully handling the malformed input as an error state, the driver triggers a fatal panic that terminates the application process immediately.
From a security impact perspective, this vulnerability represents a significant denial of service risk for applications relying on the MongoDB Go Driver to ingest untrusted data. An attacker who can supply BSON bytes directly or indirectly through API endpoints, message queues, or any other input vector capable of reaching the driver's parsing logic can exploit this flaw to crash the target application. The severity is heightened by the fact that exploitation does not require authentication; an unauthenticated actor with network access to the vulnerable service endpoint can trigger the condition remotely. This capability allows for sustained availability attacks where repeated requests can keep the application down, disrupting business operations and potentially masking other malicious activities occurring on the same infrastructure.
The technical classification of this issue aligns closely with CWE-190, which defines integer overflow or wraparound as a weakness leading to unexpected behavior when arithmetic results exceed the maximum value representable by an integer type. In the context of software security frameworks, this vulnerability facilitates availability compromise and falls under the ATT&CK technique T1499, specifically Endpoint Denial of Service via application crash. The root cause lies in insufficient validation of input data lengths before they are used for memory management or array indexing operations. While Go's runtime provides some protection against certain types of buffer overflows through bounds checking, it does not prevent panics resulting from logical errors like integer overflow that lead to invalid indices or allocations, thereby causing the application to abort execution rather than throwing a recoverable error.
It is important to note that while this vulnerability poses a severe risk for general data ingestion paths, there are specific mitigations in place within certain operational contexts of the driver. The server-monitoring path, which handles internal communication between the driver and MongoDB instances for health checks and topology discovery, includes panic recovery mechanisms. These safeguards limit the impact of such flaws to scenarios resulting in server-selection failures rather than full process termination. However, this protection does not extend to user-facing application logic where developers directly parse BSON documents from external sources. Therefore, applications that perform custom parsing or validation using raw BSON bytes remain fully exposed to exploitation unless they implement their own robust input sanitization and length verification checks prior to passing data to the driver's core parsing functions.
To mitigate this vulnerability, organizations must ensure they are running a patched version of the MongoDB Go Driver where integer overflow conditions in value-length handling have been addressed with proper bounds checking and safe arithmetic operations. Application developers should implement strict validation layers that verify BSON document structure and length constraints before invoking driver methods for untrusted data. Additionally, deploying runtime protection mechanisms such as panic recovery wrappers around critical parsing functions can provide a secondary layer of defense, ensuring that even if an overflow occurs, the application process remains alive to handle the error gracefully rather than crashing entirely. Regular security audits focusing on input validation and memory safety in Go applications are recommended to identify similar patterns across other libraries used within the stack.