# CVE-2026-34361: HAPI FHIR SSRF and credential leak in FHIR Validator

Source: https://junglewise.ai/threats/cve-2026-34361-hapi-fhir-ssrf-and-credential-leak-in-fhir-validator  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-31. Updated: 2026-07-24  
License: CC BY 4.0 with a link back

CVE-2026-34361 · Severity: critical · CVSS 9.3 · Published 2026-03-31

HAPI FHIR is a Java-based implementation of the HL7 FHIR standard used for healthcare data interoperability. A vulnerability in its validation service allows unauthenticated attackers to trick the system into sending sensitive authentication tokens (such as API keys and passwords) to a server they control. This could lead to the theft of credentials used to access healthcare registries or clinical data repositories, potentially resulting in unauthorized access to patient health records.

Technologies: [Hapifhir Hl7 Fhir Core](https://junglewise.ai/threats/technologies/hl7-fhir-core), [ca.uhn.hapi.fhir:org.hl7.fhir.validation (Maven)](https://junglewise.ai/threats/technologies/ca-uhn-hapi-fhir-org-hl7-fhir-validation). Vendors: [Hapifhir](https://junglewise.ai/threats/vendors/hapifhir), [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2026-34361 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34361 being exploited in the wild.

**How severe is CVE-2026-34361?** Critical severity, with a CVSS score of 9.3, published 31 March 2026.

**Which products and versions are affected?** HAPI FHIR FHIR Core Validation Resources < 6.9.4; ca.uhn.hapi.fhir:org.hl7.fhir.validation (Maven) ECOSYSTEM:introduced=0,fixed=6.9.4.

**Is there a fix for CVE-2026-34361?** Yes. ca.uhn.hapi.fhir:org.hl7.fhir.validation (Maven): upgrade to 6.9.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-34361 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-34361?** Check whether you run HAPI FHIR FHIR Core Validation Resources, Hapifhir Hl7 Fhir Core or ca.uhn.hapi.fhir:org.hl7.fhir.validation (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- ca.uhn.hapi.fhir:org.hl7.fhir.validation (Maven): upgrade to 6.9.4 or later

  ```sh
  # set ca.uhn.hapi.fhir:org.hl7.fhir.validation to 6.9.4 in your pom.xml or build.gradle
  ```


## Technical details

The FHIR Validator HTTP service exposes an unauthenticated '/loadIG' endpoint that accepts an 'ig' parameter and passes it to IgLoader.loadIg() without validation, leading to Server-Side Request Forgery (SSRF). A secondary flaw exists in ManagedWebAccessUtils.getServer(), which uses a startsWith() comparison to determine if credentials should be attached to an outbound request. An attacker can register a domain that prefix-matches a legitimate configured FHIR server (e.g., 'legit-server.com.attacker.com') to capture Bearer tokens, Basic auth credentials, or API keys. The vulnerability is further amplified by the SimpleHTTPClient manually following redirects and re-evaluating credential attachment on each hop. The issue is fixed in version 6.9.4 by implementing proper URL origin comparison.

## Affected products

- hapifhir org.hl7.fhir.validation < 6.9.4

## Identifiers

- CVE-2026-34361
- GHSA-vr79-8m62-wh98

## Timeline

- 2026-03-27: advisory: GitHub Security Advisory published
- 2026-03-31: disclosed: CVE published to NVD
- 2026-03-31: patched: Fix released in version 6.9.4

## References

- [https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-vr79-8m62-wh98](https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-vr79-8m62-wh98)

## Related threats

- [HAPI FHIR SHCParser DEFLATE infinite loop denial of service](https://junglewise.ai/threats/cve-2026-81876-hapi-fhir-shcparser-deflate-infinite-loop-denial-of-service)
- [HAPI FHIR SHCParser unbounded DEFLATE decompression denial of service](https://junglewise.ai/threats/cve-2026-81875-hapi-fhir-shcparser-unbounded-deflate-decompression-denial-of)
- [HAPI FHIR ReDoS in FHIRPathEngine](https://junglewise.ai/threats/cve-2026-49485-hapi-fhir-redos-in-fhirpathengine)
- [HAPI FHIR ReDoS in FHIRPathEngine](https://junglewise.ai/threats/cve-2026-45367-hapi-fhir-redos-in-fhirpathengine)
- [HAPI FHIR ReDoS in DSTU2 FHIRPathEngine](https://junglewise.ai/threats/cve-2026-55470-hapi-fhir-redos-in-dstu2-fhirpathengine)