CVE-2026-34361 HAPI FHIR: Unauthenticated SSRF via /loadIG Chains with startsWith() Credential Leak for Authentication Token Theft
Attackers can exploit an unauthenticated SSRF endpoint and a credential matching flaw to steal authentication tokens from configured FHIR servers.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-34361?
CVE-2026-34361 is a critical server-side request forgery vulnerability in hapifhir org.hl7.fhir.core, published on 31 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-552
Which versions are affected by CVE-2026-34361?
2 open source packages ship an affected version, including ca.uhn.hapi.fhir:org.hl7.fhir.validation. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
ca.uhn.hapi.fhir:org.hl7.fhir.validation Maven | All versions | 6.9.4 |
ca.uhn.hapi.fhir:org.hl7.fhir.validation Maven | All versions | 6.9.4 |
Products include Hapifhir Hl7 Fhir Core.
How do I fix CVE-2026-34361?
Upgrade ca.uhn.hapi.fhir:org.hl7.fhir.validation to 6.9.4 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-34361 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34361 exists.
Other vulnerabilities in hapifhir org.hl7.fhir.core
- CVE-2026-55471 HAPI FHIR: XXE in XsltUtilities.saxonTransform via unhardened Saxon TransformerFactory
- CVE-2023-24057 MITM based Zip Slip in `ca.uhn.hapi.fhir:org.hl7.fhir.core`
- CVE-2026-55470 HAPI FHIR: DSTU2 FHIRPathEngine.matches() missing RegexTimeout protection allows ReDoS
- CVE-2023-28465 HL7 FHIR Partial Path Zip Slip due to bypass of CVE-2023-24057
- CVE-2026-34359 HAPI FHIR: Authentication Credential Leakage via Improper URL Prefix Matching on HTTP Redirect in HAPI FHIR Core
Sources
Also known as GHSA-vr79-8m62-wh98, ROOT-APP-MAVEN-CVE-2026-34361.