CVE-2026-9749

Name of the Vulnerable Software and Affected Versions MongoDB (affected versions not specified)

Description A buffer overflow can occur during the execution of an aggregation pipeline using the internal $exchange stage. This happens when the stage is configured with key-range partitioning and order-preserving delivery. If a single key range generates a volume of documents sufficient to fill its exchange buffer, causing many results to be routed to the same consumer, the server fails to update the internal high watermark for that key range as intended.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.