CVE-2026-34361CWE-552

HAPI FHIR: Unauthenticated SSRF via /loadIG Chains with startsWith() Credential Leak for Authentication Token Theft

Critical · published March 31, 2026

CVSS v3.1
9.3
EPSS
0%
Percentile
35.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.3 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00422 · 35.5th percentile
Weakness
CWE-552 · Files or Directories Accessible to External Parties
Published
2026-03-31T16:56Z
EPSS history
Timeline
  • 31 MAR 16:56Z
    HAPI FHIR: Unauthenticated SSRF via /loadIG Chains with startsWith() Credential Leak for Authentication Token Theft
    cvelistv5