CVE-2026-18953
Bulletin ID: 2026-075-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 08/05/2026 12:30 PM PDT Description: The AWS Transform MCP Server (awslabs.aws-transform-mcp-server) is an open-source Model Context Protocol (MCP) server that runs locally on a developer's machine and lets AI-powered assistants interact with AWS Transform to run code-transformation jobs and retrieve their artifacts. We identified CVE-2026-18953. Improper limitation of a pathname to a restricted directory in the get_resource tool in awslabs.aws-transform-mcp-server before 0.1.5 might allow a context-dependent actor to write arbitrary files outside the intended working directory via the savePath parameter, which could lead to local code execution. Impacted versions: >=0.1.0 AND <=0.1.4 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.
CSIRTS triage
- What
- Improper pathname limitation in the get_resource tool allows writing arbitrary files outside the intended directory via savePath parameter.
- Who is affected
- Developers using AWS Transform MCP Server versions 0.1.0 through 0.1.4.
- Urgency
- High urgency; local code execution is possible through arbitrary file write capability.
- Action
- Update AWS Transform MCP Server to version 0.1.5 or later.
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Exploitation outlook
- Low exploitation risk0.15% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 5% of all EPSS-scored CVEs.
Advisory coverage (2)
External references
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