CVE-2026-107325 in Go Driver
Summary
by MITRE • 10/08/2026
Improper validation of a BSON array length in the MongoDB Go Driver can cause an out-of-bounds index and runtime panic when an application calls bson.RawArray.Validate or bsoncore.Array.Validate on a malformed four-byte array. An unauthenticated actor who can supply raw BSON array data to an affected application may terminate an unprotected application process, causing a denial of service. No confidentiality or integrity impact has been identified.
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Analysis
by VulDB Data Team • 10/08/2026
The vulnerability described involves a critical input validation failure within the MongoDB Go Driver, specifically affecting how it processes BSON (Binary JSON) arrays. When applications utilize functions such as bson.RawArray.Validate or bsoncore.Array.Validate to inspect incoming data structures, they rely on internal logic to ensure that array lengths and indices are consistent with actual memory allocations. In this specific scenario, a malformed four-byte array triggers an improper validation mechanism where the driver fails to correctly verify the bounds of the array before attempting to access its elements. This oversight leads directly to an out-of-bounds index error during runtime execution. Because Go applications typically do not handle such low-level memory errors gracefully without explicit panic recovery mechanisms, this condition results in a fatal runtime panic that abruptly terminates the application process.
From a security perspective, this flaw represents a classic denial of service vector arising from insufficient input validation. An unauthenticated attacker who has the ability to supply raw BSON array data to an affected MongoDB Go Driver instance can exploit this weakness by crafting a specifically malformed four-byte payload. Upon processing this malicious input, the application will crash immediately due to the runtime panic. This effectively allows the attacker to disrupt service availability without requiring any form of authentication or prior access privileges. The impact is strictly limited to availability, as there are no identified implications for data confidentiality or integrity; however, in production environments where high uptime and reliability are paramount, even a single point of failure that can be triggered remotely poses a significant operational risk.
This vulnerability aligns with CWE-20 Improper Input Validation, which covers cases where software fails to verify the correctness, completeness, and appropriateness of inputs before processing them. Furthermore, in the context of the MITRE ATT&CK framework, this behavior is consistent with techniques used for Denial of Service attacks, particularly those that target application logic or resource exhaustion through malformed requests. The specific mechanism here involves exploiting a parsing routine to cause a crash rather than consuming excessive resources over time, which distinguishes it from some other DoS vectors but remains equally disruptive in terms of service interruption.
To mitigate this risk, developers should ensure they are using the latest patched version of the MongoDB Go Driver where this validation logic has been corrected. If immediate patching is not feasible, application-level mitigations can be implemented by wrapping calls to bson.RawArray.Validate and bsoncore.Array.Validate within recover blocks that catch panics and handle them gracefully without terminating the entire process. Additionally, implementing strict input filtering at the network or API gateway level before data reaches the Go driver can provide an additional layer of defense against malformed BSON payloads. Regular security audits focusing on third-party library usage and their handling of untrusted inputs are also recommended to prevent similar vulnerabilities in other components of the software stack.