CVE-2026-104005

Incorrect authorization in MongoDB Server router for bulk writes to system namespaces

Published Oct 13, 2026 CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mongodb
Mongodb mongodb Server
Vendors & Products Mongodb
Mongodb mongodb Server
Type Values Removed Values Added
Weaknesses CWE-863
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'}

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mongodb
Published
Updated
Oct 15, 2026, 7:14 PM
Reserved
Oct 1, 2026, 4:22 PM
Status
Awaiting Analysis
Published
Oct 13, 2026, 4:17 PM
Modified
Oct 15, 2026, 8:38 PM