CVE-2026-18954 - Incorrect authorization in the aggregation pipeline tool in Amazon AWS Labs DocumentDB MCP Server

unknownCVE-2026-18954

Bulletin ID: 2026-076-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 08/05/2026 13:00 PM PDT Description: Amazon DocumentDB MCP Server is an open-source Model Context Protocol (MCP) server that enables AI assistants to interact with Amazon DocumentDB databases. We identified CVE-2026-18954, an incorrect authorization issue where write-capable aggregation pipeline stages ($out, $merge) bypass the read-only mode enforcement logic, potentially allowing an authenticated MCP client to perform write operations on the connected database. Impacted versions: < 1.0.12 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.

CSIRTS triage

vendor: Amazon AWS product: DocumentDB MCP Server Authentication bypassaffected: <1.0.12

What: Incorrect authorization in aggregation pipeline allows write-capable stages to bypass read-only mode enforcement.
Who is affected: Deployments of AWS DocumentDB MCP Server versions before 1.0.12.
Urgency: High urgency; authenticated clients can perform unauthorized write operations on databases despite read-only mode.
Action: Update DocumentDB MCP Server to version 1.0.12 or later.

AI-assisted analysis generated from the source advisory — verify against the original.

⚡ Watch DocumentDB MCP Server

Get an email when a new DocumentDB MCP Server advisory drops — max one per day, one-click unsubscribe.

Details

Source: AWS Security Bulletins (INTL · vendor-psirt · site)
Severity: unknown
Published: 2026-08-05
Exploitation: Not in CISA KEV at last sync

Original advisory: https://aws.amazon.com/security/security-bulletins/rss/2026-076-aws/

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-189540.10% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 1% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-18954	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

mediumCVE-2026-18954: Incorrect authorization in the aggregation pipeline tool in Amazon AWS Labs DocumentDB MCP Ser…nvd