# CVE-2026-104005: Incorrect authorization in MongoDB Server router for bulk writes to system namespaces

CVE-2026-104005 is fixed in MongoDB on 1 platform by MongoDB 9.0.4 (version 9.0.4), released October 8, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-104005
- Priority: High
- CVSS: 7.1
- EPSS: 0.0024
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Oct 13, 2026
- Weakness: CWE-617: Reachable Assertion
- Vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-104005

## Description

A security issue was discovered in MongoDB mongos (the sharded cluster router) where an authenticated user with readWrite privileges could crash the mongos process by crafting a specially formed aggregation pipeline. The issue leverages an internal aggregation stage that lacks proper authorization checks despite being intended for internal use, allowing a subsequent stage to be forced to execute on the router under conditions it was not designed to handle. This results in an unhandled fatal error that causes the mongos process to immediately abort, resulting in denial of service for all clients routed through the affected mongos instance.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Windows apps | MongoDB | 9.0.4 | [MongoDB 9.0.4](https://patchblox.com/security/data/fix/windows-app/mongodb.server-9.0.4.md) | Oct 8, 2026 |

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Data as of 2026-11-10T01:44:33Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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