What is CVE-2026-34361?

CVE-2026-34361 is a critical-severity vulnerability in Hapifhir Hl7 Fhir Core, classified under Files or Directories Accessible to External Parties. CVSS score: 9.3/10. Published 2026-03-31.

How severe is CVE-2026-34361?

Critical severity. CVSS v3 base score is 9.3 out of 10.

Vulnerability in Hapifhir Hl7 Fhir Core

CVE-2026-34361

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.

EPSS: 0.003 (22.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.3 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N.

Affected products

Hapifhir Hl7_fhir_core
Hapifhir Org.hl7.fhir.core — versions < 6.9.4

Weakness classification (CWE)

CWE-552 — Files or Directories Accessible to External Parties

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-34361?: CVE-2026-34361 is a critical-severity vulnerability in Hapifhir Hl7 Fhir Core, classified under Files or Directories Accessible to External Parties. CVSS score: 9.3/10. Published 2026-03-31.
How severe is CVE-2026-34361?: Critical severity. CVSS v3 base score is 9.3 out of 10.