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.
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History

Tue, 13 Oct 2026 19:15:00 +0000

Type Values Removed Values Added
First Time appeared Mongodb
Mongodb mongodb Server
Vendors & Products Mongodb
Mongodb mongodb Server

Tue, 13 Oct 2026 17:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-863

Tue, 13 Oct 2026 16:30:00 +0000

Type Values Removed Values Added
Description Incorrect authorization in the write routing component of the MongoDB Server sharded cluster router can cause bulk write operations to skip authorization checks for the target namespace. An authenticated user with write privileges on a regular collection who submits a bulk write that targets an internal system namespace may have the operation accepted by the router even though they are not authorized to write to that namespace. The resulting impact depends on the system namespace targeted. 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.
Weaknesses CWE-617
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Tue, 13 Oct 2026 16:00:00 +0000

Type Values Removed Values Added
Description Incorrect authorization in the write routing component of the MongoDB Server sharded cluster router can cause bulk write operations to skip authorization checks for the target namespace. An authenticated user with write privileges on a regular collection who submits a bulk write that targets an internal system namespace may have the operation accepted by the router even though they are not authorized to write to that namespace. The resulting impact depends on the system namespace targeted.
Title Incorrect authorization in MongoDB Server router for bulk writes to system namespaces
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mongodb

Published:

Updated: 2026-10-13T16:07:41.353Z

Reserved: 2026-10-01T16:22:56.660Z

Link: CVE-2026-104005

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-13T16:17:11.137

Modified: 2026-10-13T17:17:15.380

Link: CVE-2026-104005

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-13T19:00:06Z

Weaknesses