# CVE-2026-5170: Users could trigger a crash of mongod primaries during promotion to sharded

CVE-2026-5170 is fixed in MongoDB on 1 platform by MongoDB 8.0.18 (version 8.0.18), released January 15, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-5170
- Priority: Routine
- CVSS: 6.0
- EPSS: 0.0021
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 30, 2026
- Weakness: CWE-617: Reachable Assertion
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-5170

## Description

A user with access to the cluster with a limited set of privilege actions can trigger a crash of a mongod process during the limited and unpredictable window when the cluster is being promoted from a replica set to a sharded cluster. This may cause a denial of service by taking down the primary of the replica set.  This issue affects MongoDB Server v8.2 versions prior to 8.2.2, MongoDB Server v8.0 versions between 8.0.18, MongoDB Server v7.0 versions between 7.0.31.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | MongoDB | 8.0.18 | [MongoDB 8.0.18](https://patchblox.com/security/data/fix/windows-app/mongodb.server-8.0.18.md) | Jan 15, 2026 |

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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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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