CVE-2026-34361: Hapifhir HL7 Fhir Core

Critical severity, CVSS 9.3. EPSS: 0.4% chance of exploitation in the next 30 days.

HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to version 6.9.4, the FHIR Validator HTTP service exposes an unauthenticated "/loadIG" endpoint that makes outbound HTTP requests to attacker-controlled URLs. Combined with a startsWith() URL prefix matching flaw in the credential provider (ManagedWebAccessUtils.getServer()), an attacker can steal authentication tokens (Bearer, Basic, API keys) configured for legitimate FHIR servers by registering a domain that prefix-matches a configured server URL. This issue has been patched in version 6.9.4.

Affected products

• Hapifhir HL7 Fhir Core: before 6.9.4 (fixed in 6.9.4)

Published 2026-03-31. Last modified 2026-07-24.