AWS patches path traversal flaw in HealthOmics MCP Server

Amazon Web Services released a security update on July 17, 2026, to address a path traversal vulnerability in its HealthOmics service. The company identified CVE-2026-15415, which allows attackers to write arbitrary files outside intended directories if they can influence the Model Context Protocol agent.

The vulnerability exists in the linting tools of the aws-healthomics-mcp-server component. According to the AWS Security Bulletin, improper limitations on pathnames in versions prior to 0.0.36 enable directory traversal sequences within the workflow_files input. This could allow an actor to write controlled content to arbitrary locations outside the intended workflow bundle directory.

Technical details and disclosure

AWS classified the bulletin as important and requiring attention. The issue stems from how the server handles pathname restrictions in its workflow linters. An attacker capable of influencing the MCP agent could exploit the flaw by injecting directory traversal sequences into the workflow_files input parameter. This bypasses the intended directory constraints and permits unauthorized file writes.

Rotimi Akinyele from Deriv collaborated with AWS on this issue through the coordinated vulnerability disclosure process. AWS thanked Akinyele for reporting the flaw responsibly. The vendor addressed the problem in version 0.0.36 of the aws-healthomics-mcp-server, which restricts pathname access appropriately.

Scope and impact

AWS HealthOmics is a HIPAA-eligible service that manages compute, storage, and workflow engine infrastructure for bioinformatics analyses. The service supports clinical diagnostics, drug discovery, and agricultural research at scale. The vulnerability specifically impacts the aws-healthomics-mcp-server component, which facilitates interaction with these workflows.

Only versions 0.0.35 and earlier of the aws-healthomics-mcp-server are affected by CVE-2026-15415. Organizations running older versions of this server component are exposed to potential arbitrary file write attacks. AWS recommends that users upgrade to the latest version immediately to mitigate this risk.

What should you do?

AWS advises customers to upgrade their aws-healthomics-mcp-server to version 0.0.36 or later. Users who have forked or derived code from the server must ensure their custom versions incorporate the new fixes. The vendor urges all administrators to verify their current version numbers and apply the patch without delay.

Background: Coordinated vulnerability disclosure

Coordinated vulnerability disclosure reveals software flaws to vendors before public release. Small teams must patch during this quiet period. Monitor vendor security pages, prioritize critical updates, and verify that your IT provider tracks these disclosures to prevent exploitation of known weaknesses before public patches arrive.

Read the full guide: Coordinated Vulnerability Disclosure for Small Teams

What to do and how to stay safe: AWS

• Check your current aws-healthomics-mcp-server version to see if it is 0.0.35 or earlier.
• Upgrade to version 0.0.36 or the latest available release as soon as possible.
• Review any forked or derivative code to ensure it includes the security fixes from the official update.
• Monitor AWS security bulletins for further updates on this or related HealthOmics components.

Step-by-step guide: Risk-Based Vulnerability Management: Prioritize Fixes by Actual Danger

General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.

Frequently asked questions

What is CVE-2026-15415?

CVE-2026-15415 is a path traversal and arbitrary file write vulnerability in the workflow linters of the aws-healthomics-mcp-server.

Which versions are affected?

The vulnerability affects aws-healthomics-mcp-server versions 0.0.35 and earlier.

Is there a fix available?

Yes, AWS addressed the issue in aws-healthomics-mcp-server version 0.0.36.