CVE-2026-18953 in aws-transform-mcp-server
Summary
by MITRE • 08/05/2026
Improper limitation of a pathname to a restricted directory in the get_resource tool in Amazon awslabs.aws-transform-mcp-server 0.1.0 through 0.1.4 might allow a context-dependent actor to write arbitrary files outside the intended working directory via the savePath parameter.
To remediate this issue, users should upgrade to version 0.1.5 or later.
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Analysis
by VulDB Data Team • 08/05/2026
This vulnerability represents a classic path traversal flaw that exploits improper input validation in the aws-transform-mcp-server tool developed by Amazon awslabs. The issue manifests when the get_resource utility processes the savePath parameter without adequate sanitization or restriction mechanisms, allowing malicious actors to manipulate file system operations beyond the intended directory boundaries. Such vulnerabilities fall under CWE-22 Path Traversal and are categorized as privilege escalation risks within the ATT&CK framework. The vulnerability exists specifically in versions 0.1.0 through 0.1.4 of the aws-transform-mcp-server package, where the tool fails to properly validate user-supplied paths against a designated working directory.
The technical exploitation occurs when an attacker crafts a malicious savePath parameter containing directory traversal sequences such as ../ or ..\ that bypass directory restrictions. This allows the context-dependent actor to write files anywhere within the system's file hierarchy rather than being confined to the intended working directory. The vulnerability creates an arbitrary file write condition that can be leveraged for various malicious purposes including privilege escalation, data exfiltration, or system compromise. The flaw essentially removes the sandboxing mechanism that should protect the application from unauthorized file system access beyond its designated scope.
The operational impact of this vulnerability extends beyond simple file manipulation, potentially enabling attackers to overwrite critical system files, inject malicious code into the application's execution path, or establish persistence mechanisms within the target environment. When combined with other exploitation techniques, this vulnerability can serve as a foothold for more extensive attacks within cloud infrastructure environments where aws-transform-mcp-server might be deployed. The risk is particularly elevated in containerized or microservices architectures where such tools might be running with elevated privileges.
Security practitioners should prioritize upgrading to version 0.1.5 or later as the primary remediation strategy, as this release includes proper input validation and path restriction mechanisms that prevent directory traversal attacks. Additional mitigations include implementing strict file system access controls, monitoring for unusual file system operations, and applying principle of least privilege configurations for any processes utilizing this tool. Organizations should also conduct thorough security assessments to identify other potentially vulnerable components within their AWS transformation toolchains that might share similar architectural flaws. The vulnerability highlights the importance of input validation and proper sandboxing in cloud-native applications, particularly those handling user-supplied data in file system operations.