AWS HealthLake MCP Server SSRF via Unvalidated Pagination URL

Bulletin ID: 2026-054-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 07/14/2026 13:00 PM PDT Description: AWS HealthLake MCP Server (awslabs.healthlake-mcp-server) is a Model Context Protocol server that enables AI assistants to interact with AWS HealthLake FHIR datastores. We identified CVE-2026-15643 a server-side request forgery in the pagination handling component in AWS awslabs.healthlake-mcp-server before 0.0.14 on all platforms might allow a remote authenticated user to exfiltrate AWS temporary security credentials to an arbitrary endpoint via a crafted next_token parameter. The server does not validate that pagination URLs point back to the expected HealthLake endpoint, allowing an actor to redirect subsequent requests to an actor-controlled server. Impacted versions:   Resolution: This issue has been addressed in awslabs.healthlake-mcp-server version 0.0.14 . We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. Workarounds: In the interim, scope the IAM policy used by the server to least privilege rather than Resource: "*", and do not rely on the --readonly flag as a security boundary — it is an in-process guard over the mutating tools, not an IAM control, so disclosed credentials retain their full granted authority. Operators using role-based (STS) deployments should consider rotating the affected role's credentials if they suspect using an affected version. References: CVE-2026-15643 GHSA-c5vr-x62j-w6rw Acknowledgement: We would like to thank Marios Gyftos for collaborating on this issue through the coordinated vulnerability disclosure process. Please email aws-security@amazon.com with any security questions or concerns. "},"metadata":{"tags":[]}},{"fields":{"patternBoolean2":"false","id":"ams#rt-rich-textc2#pattern-data"},"metadata":{"tags":[{"name":"pattern-data","description":"Default pattern data","id":"ams#rt-rich-textc2#pattern-data","namespaceId":"rt-rich-text"}]}}]},"metadata":{"auth":{},"testAttributes":{}},"context":{"page":{"pageUrl":"https://aws.amazon.com/security/security-bulletins/2026-054-aws/"},"contentType":"page","environment":{"stage":"prod","region":"us-west-2"},"sdkVersion":"2.0.27"},"refMap":{"manifest.js":"cda3e8d042","rt-rich-text.js":"5043b0a87f","rt-rich-text.rtl.css":"6a04028f86","rt-rich-text.css":"98f5a6aee4","rt-rich-text.css.js":"3d619cc2e1","rt-rich-text.rtl.css.js":"ccdb945d3e"},"settings":{"templateMappings":{"patternHeading":"patternHeading","patternSubheading":"patternSubheading","patternDark":"patternBoolean2","title":"itemHeading","bodyText":"itemLongLoc"}}} CVE-2026-15643 - AWS HealthLake MCP Server SSRF via Unvalidated Pagination URL Bulletin ID: 2026-054-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 07/14/2026 13:00 PM PDT Description: AWS HealthLake MCP Server (awslabs.healthlake-mcp-server) is a Model Context Protocol server that enables AI assistants to interact with AWS HealthLake FHIR datastores. We identified CVE-2026-15643 a server-side request forgery in the pagination handling component in AWS awslabs.healthlake-mcp-server before 0.0.14 on all platforms might allow a remote authenticated user to exfiltrate AWS temporary security credentials to an arbitrary endpoint via a crafted next_token parameter. The server does not validate that pagination URLs point back to the expected HealthLake endpoint, allowing an actor to redirect subsequent requests to an actor-controlled server. Impacted versions:   Resolution: This issue has been addressed in awslabs.healthlake-mcp-server version 0.0.14 . We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. Workarounds: In the interim, scope the IAM policy used by the server to least privilege rather than Resource: "*", and do not rely on the --readonly flag as a security boundary — it is an in-process guard over

Severity from

no source yet

• aws.amazon.com/security/security-bulletins/rss/2026-054-aws/
• www.cve.org/CVERecord?id=CVE-2026-15643