CVE-2026-81533: MongoDB BI Connector ODBC Driver Memory-Safety Issue When Parsing Oversized LIMIT Values
An application using the MongoDB BI Connector ODBC Driver may encounter a memory-safety issue when a submitted SQL statement contains an unusually long run of digits following a LIMIT clause. The issue occurs only on connections where the driver's optional prefetch setting is enabled, and stems from the driver copying the digit sequence into a fixed-size internal buffer without checking its length. A user able to influence the numeric portion of a LIMIT clause could cause the hosting application process to terminate unexpectedly or corrupt adjacent memory in that process.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Disable the MongoDB BI Connector ODBC Driver optional prefetch setting, since the memory-safety issue occurs only when prefetch is enabled and the driver copies an oversized LIMIT digit sequence into a fixed-size buffer.
MongoDB BI Connector ODBC Driver prefetch = disabled
Event History
Frequently Asked Questions
Which deployments are affected by this issue?
Only connections with the MongoDB BI Connector ODBC Driver's optional prefetch setting enabled are affected. The vulnerable parsing path is reached when processing a SQL LIMIT clause.
What access does an attacker need to exploit it?
An attacker needs the ability to influence the numeric portion of a LIMIT clause submitted through an application using the driver. The LIMIT value must contain an unusually long sequence of digits.
What is the likely impact on an affected application?
A crafted LIMIT value can cause the hosting application process to terminate unexpectedly or corrupt adjacent memory within that process. The described impacts are integrity loss and denial of service.
What can be done if an update cannot be applied immediately?
Disable the driver's optional prefetch setting on affected connections. Also prevent untrusted input from controlling LIMIT numeric values, particularly allowing excessively long digit sequences.