# CVE-2026-9753: Server crash via malformed binary diff passed to $_internalApplyOplogUpdate.

CVE-2026-9753 is fixed in MongoDB on 1 platform by MongoDB 8.3.3 (version 8.3.3), released May 28, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-9753
- Priority: High
- CVSS: 7.2
- EPSS: 0.0030
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 9, 2026
- Weakness: CWE-1287: Improper validation of specified type of input
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-9753

## Description

The $_internalApplyOplogUpdate aggregation pipeline stage can be used to execute a document diff containing a malformed binary diff to return memory out-of-bounds or crash the server. $_internalApplyOplogUpdate can be executed by any authenticated user with access to the aggregate command.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | MongoDB | 8.3.3 | [MongoDB 8.3.3](https://patchblox.com/security/data/fix/windows-app/mongodb.server-8.3.3.md) | May 28, 2026 |

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Data as of 2026-11-08T00:53:09Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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