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TI-2026-26645 Aliases CVE-2026-34359GHSA-fgv2-4q4g-wc35

HAPI FHIR: Authentication Credential Leakage via Improper URL Prefix Matching on HTTP Redirect in HAPI FHIR Core

Priority HIGH 74CWE-346Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-346.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00164 5th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed org.hl7.fhir.core (hapifhir): 6.9.4ca.uhn.hapi.fhir:org.hl7.fhir.core (Maven): 6.9.4+1 more product

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
hapifhirorg.hl7.fhir.corebefore 6.9.46.9.4Patch availableCNA
—ca.uhn.hapi.fhir:org.hl7.fhir.core (Maven)before 6.9.46.9.4Patch availableGHSA-fgv2-4q4g-wc35
—ca.uhn.hapi.fhir:org.hl7.fhir.utilities (Maven)before 6.9.46.9.4Patch availableGHSA-fgv2-4q4g-wc35
  • org.hl7.fhir.core Vendorhapifhir Affected before 6.9.4 Fixed in 6.9.4 Patch available CNA
  • ca.uhn.hapi.fhir:org.hl7.fhir.core (Maven) Vendor— Affected before 6.9.4 Fixed in 6.9.4 Patch available GHSA-fgv2-4q4g-wc35
  • ca.uhn.hapi.fhir:org.hl7.fhir.utilities (Maven) Vendor— Affected before 6.9.4 Fixed in 6.9.4 Patch available GHSA-fgv2-4q4g-wc35

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:hapifhir:hl7_fhir_core:*:*:*:*:*:*:*:*before 6.9.4Vulnerablehapifhir
  • cpe:2.3:a:hapifhir:hl7_fhir_core:*:*:*:*:*:*:*:* Versions before 6.9.4 Vulnerable ·hapifhir

Remediation

  • Fix · CNA org.hl7.fhir.core (hapifhir) Fixed in 6.9.4
  • Fix · GHSA-fgv2-4q4g-wc35 ca.uhn.hapi.fhir:org.hl7.fhir.core (Maven) Fixed in 6.9.4 Advisory →
  • Fix · GHSA-fgv2-4q4g-wc35 ca.uhn.hapi.fhir:org.hl7.fhir.utilities (Maven) Fixed in 6.9.4 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34359
  2. 2026-10-03 Alias added: GHSA-fgv2-4q4g-wc35

References

Exploit 1

Advisory 1

Other 1

  • TI-2026-26647 HAPI FHIR: Unauthenticated SSRF via /loadIG Chains with startsWith() Credential Leak for Authentication Token Theft CVSS 3.1CRITICAL 9.3
  • TI-2026-40028 HAPI FHIR: XXE in XsltUtilities.saxonTransform via unhardened Saxon TransformerFactory CVSS 4.0HIGH 8.7
  • TI-2026-40027 HAPI FHIR: DSTU2 FHIRPathEngine.matches() missing RegexTimeout protection allows ReDoS CVSS 3.1HIGH 7.5
  • TI-2023-09835 HL7 (Health Level 7) FHIR Core Libraries before 5.6.92 allow attackers to extract files… CVSS 3.1HIGH 8.1
  • TI-2023-13005 The package-decompression feature in HL7 (Health Level 7) FHIR Core Libraries before… CVSS 3.1HIGH 7.5
  • TI-2026-26646 HAPI FHIR: Unauthenticated Blind SSRF via /loadIG Endpoint Enables Internal Network Probing CVSS 3.1MEDIUM 5.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences