# CVE-2026-18704: Improper Authorization in MongoDB Aggregation Framework Allows Read-Only User to Perform Unauthorized Write Operations

> CVE-2026-18704: Improper Authorization in MongoDB Aggregation Framework Allows Read-Only User to Perform Unauthorized Write Operations. CVSS 6.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-18704
Last updated: 2026-10-23T21:10:00Z

- Published: 2026-08-11 18:37 UTC · Updated: 2026-10-23 21:10 UTC · Assigner: mongodb
- CVSS: 6.5 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- EPSS: 0.29%, 21th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-862

## Description

An issue in MongoDB Server's aggregation framework could allow an authenticated user with only read privileges to perform write operations against collections they should not be able to modify. This is due to an internal-use aggregation stage being reachable by external clients without an appropriate authorization check on its embedded operations.

## Affected vendors and products

- MongoDB: MongoDB Server

## Tracked companies

- [MongoDB Atlas](https://rewindex.com/company/mongodb-atlas.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-18704)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-18704)
- [https://jira.mongodb.org/browse/SERVER-129936](https://jira.mongodb.org/browse/SERVER-129936)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-18704 · Markdown: https://rewindex.com/cve/CVE-2026-18704.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-18704 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:09:46.533Z