CVE-2026-9743
Received Received - Intake
Denial of Service in MongoDB Server via Null Sub-Pipeline Dereference

Publication date: 2026-06-09

Last updated on: 2026-06-09

Assigner: MongoDB, Inc.

Description
In MongoDB Server 8.0, an aggregation stage can leave its _subPipeline field null during processing of certain pipelines. If a getMore is subsequently issued on the same cursor, the server may dereference this null sub-pipeline when reattaching to the operation context, accessing an invalid address and crashing the process. This issue allows an authenticated user who can run aggregation pipelines to cause a denial of service by issuing a specially crafted aggregation followed by getMore on affected versions.
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Meta Information
Published
2026-06-09
Last Modified
2026-06-09
Generated
2026-06-10
AI Q&A
2026-06-10
EPSS Evaluated
N/A
NVD
CVE-2026-9743
EUVD
EUVD-2026-35861
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
mongodb mongodb_server From 8.0 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.
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Executive Summary

In MongoDB Server 8.0, there is a vulnerability where an aggregation stage can leave its _subPipeline field null during the processing of certain aggregation pipelines.

If a getMore command is issued on the same cursor afterward, the server may attempt to dereference this null _subPipeline field when reattaching to the operation context, which leads to accessing an invalid memory address and causes the server process to crash.

This means that an authenticated user who has permission to run aggregation pipelines can deliberately cause a denial of service by issuing a specially crafted aggregation followed by a getMore command on affected versions.

Impact Analysis

This vulnerability can be exploited by an authenticated user with permission to run aggregation pipelines to cause the MongoDB server process to crash.

The impact is a denial of service (DoS), which means the database service becomes unavailable until it is restarted or recovered.

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