# CVE-2026-9743: Aggregation sub-pipeline null dereference may allow DoS via crafted getMore

CVE-2026-9743 is fixed in MongoDB on 1 platform by MongoDB 8.2.3 (version 8.2.3), released December 16, 2025. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-9743
- Priority: High
- CVSS: 7.1
- EPSS: 0.0031
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 9, 2026
- Weakness: CWE-476: NULL pointer dereference
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-9743

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | MongoDB | 8.2.3 | [MongoDB 8.2.3](https://patchblox.com/security/data/fix/windows-app/mongodb.server-8.2.3.md) | Dec 16, 2025 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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