CVE-2026-18888 in BI Connector ODBC Driver
Summary
by MITRE • 08/12/2026
The MongoDB BI Connector ODBC Driver converts floating point column values into text without checking that the result fits within the destination buffer. When an application reads a sufficiently large floating point value as text, the driver may write beyond the end of that buffer and corrupt adjacent memory. A user who can store data in a collection read through the BI Connector could use this to crash the application performing the read.
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Analysis
by VulDB Data Team • 08/12/2026
The MongoDB BI Connector ODBC Driver vulnerability represents a critical buffer overflow condition that arises from improper handling of floating point to text conversion operations. This flaw exists within the driver's data processing pipeline where numeric values are transformed for external consumption through the ODBC interface. The vulnerability stems from a lack of bounds checking during the string conversion process, allowing maliciously crafted large floating point numbers to cause memory corruption when converted to text format. The root cause aligns with common software security weaknesses categorized under CWE-121, which addresses buffer overflow conditions in stack-based buffers, though this specifically manifests in heap-based memory corruption due to dynamic allocation patterns within the ODBC driver architecture.
The operational impact of this vulnerability extends beyond simple application crashes to potentially enable more sophisticated attack vectors. When an attacker can store data in a MongoDB collection that is subsequently read through the BI Connector, they possess the capability to craft floating point values large enough to trigger buffer overflows during text conversion. This creates a path for arbitrary code execution or denial of service conditions depending on how the consuming application handles memory corruption. The vulnerability operates at the intersection of data processing and memory management within database connectivity layers, making it particularly dangerous in enterprise environments where BI tools frequently query MongoDB collections through ODBC interfaces. Security frameworks such as ATT&CK T1059.008 categorize this type of attack as abuse of remote services through command injection or memory corruption techniques.
Mitigation strategies for this vulnerability must address both the immediate code-level fixes and broader architectural considerations within database connectivity systems. The primary fix requires implementing proper bounds checking during floating point to text conversion operations, ensuring that destination buffers are adequately sized to handle the maximum possible string representation of floating point values. This includes validating input data ranges and employing safe string conversion functions that prevent buffer overflows. Organizations should also implement strict access controls on MongoDB collections that are exposed through BI Connectors, limiting write privileges to trusted users only. Additionally, regular security testing of database connectivity layers using fuzzing techniques can help identify similar buffer overflow conditions in other components of the data processing pipeline, as recommended by industry standards for secure software development practices.