CVE-2026-18954Hinoki check available

Unauthorized database writes via aggregation stages

Published Aug 5, 2026 · Updated Aug 5, 2026

Incorrect authorization in Amazon DocumentDB MCP Server before 1.0.12 allows attackers to write to connected databases. The aggregate tool passes $out and $merge stages to DocumentDB without applying the server's read-only-mode validation. Exploitation requires an authenticated MCP client and database credentials with write privileges, and it defeats the default read-only safety boundary without affecting confidentiality or availability.

CVSS severity5.7
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
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Summary

What happened

Incorrect authorization in Amazon DocumentDB MCP Server before 1.0.12 allows attackers to write to connected databases. The aggregate tool passes $out and $merge stages to DocumentDB without applying the server's read-only-mode validation. Exploitation requires an authenticated MCP client and database credentials with write privileges, and it defeats the default read-only safety boundary without affecting confidentiality or availability.

The record

CVE
CVE-2026-18954
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
Amazon Web Services
Product
Amazon DocumentDB MCP Server
Classifications
CWE-863, CAPEC-122, T1565.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.0.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Amazon Web Services · Amazon DocumentDB MCP Serverversion=0 <1.0.12

Published CVSS scores

5.7Amazon Web ServicesCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
5.5Amazon Web ServicesCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
CAPEC-122Privilege Abuse
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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