Using MaxKey() may crash the server_CVE-2026-9749

7.1 / 10

HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Description

This issue can occur when running an aggregation pipeline that uses the internal $exchange stage configured with key-range partitioning and order-preserving delivery. If a single key range produces enough documents to fill its exchange buffer (that is, many results are routed to the same consumer), the server reaches the code path where a full per-consumer buffer is detected but the internal "high watermark" for that key range is not updated as intended.

Basic Information

ID CVE-2026-9749

Source mongodb

Published Jun 9, 2026 at 22:10

Affected Product

Vendor MongoDB

Product MongoDB Server

Version 8.3.0

Affected Versions MongoDB MongoDB Server 8.3.0
MongoDB MongoDB Server 8.2.0
MongoDB MongoDB Server 8.0.0
MongoDB MongoDB Server 7.0.0

CWE Classification

CWE-617

References

jira.mongodb.org /browse/SERVER-124031

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    "published": "2026-06-09T22:10:45.815Z",
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