HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.10, the fix for CVE-2026-45367 incompletely patched the DSTU2 module, leaving FHIRPathEngine.matches() in org.hl7.fhir.dstu2/utils/FHIRPathEngine.java to call raw String.matches(sw) without RegexTimeout protection while replaceMatches() was updated, allowing an unauthenticated attacker to trigger catastrophic regex backtracking and exhaust server CPU. This issue is fixed in version 6.9.10.
HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.10, org.hl7.fhir.utilities.XsltUtilities saxonTransform(...) overloads instantiated a bare net.sf.saxon.TransformerFactoryImpl() without ACCESS_EXTERNAL_DTD or ACCESS_EXTERNAL_STYLESHEET restrictions, allowing an attacker who controls or can tamper with transformed XML to trigger XML External Entity injection for local file disclosure and blind XXE or SSRF to arbitrary URLs reachable from the host. This issue is fixed in version 6.9.10.
HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to version 6.9.4, the /loadIG HTTP endpoint in the FHIR Validator HTTP service accepts a user-supplied URL via JSON body and makes server-side HTTP requests to it without any hostname, scheme, or domain validation. An unauthenticated attacker with network access to the validator can probe internal network services, cloud metadata endpoints, and map network topology through error-based information leakage. With explore=true (the default for this code path), each request triggers multiple outbound HTTP calls, amplifying reconnaissance capability. This issue has been patched in version 6.9.4.
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.
HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to version 6.9.4, ManagedWebAccessUtils.getServer() uses String.startsWith() to match request URLs against configured server URLs for authentication credential dispatch. Because configured server URLs (e.g., http://tx.fhir.org) lack a trailing slash or host boundary check, an attacker-controlled domain like http://tx.fhir.org.attacker.com matches the prefix and receives Bearer tokens, Basic auth credentials, or API keys when the HTTP client follows a redirect to that domain. This issue has been patched in version 6.9.4.
The package-decompression feature in HL7 (Health Level 7) FHIR Core Libraries before 5.6.106 allows attackers to copy arbitrary files to certain directories via directory traversal, if an allowed directory name is a substring of the directory name chosen by the attacker. NOTE: this issue exists because of an incomplete fix for CVE-2023-24057.