CVE-2026-34359
Hapifhir Hl7 Fhir Core ≤ 6.9.4
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-34359 is a high-severity Origin Validation Error (CWE-346) vulnerability in Hapifhir Hl7 Fhir Core. Its CVSS base score is 7.4 (High).
Operationally, ranked at the 10th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and IA-3 (Device Identification and Authentication) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-34359 is a vulnerability in HAPI FHIR, a complete Java implementation of the HL7 FHIR standard for healthcare interoperability. In versions prior to 6.9.4, the ManagedWebAccessUtils.getServer() function uses String.startsWith() to match request URLs against configured server URLs for authentication credential dispatch. This approach lacks trailing slash or host boundary checks, allowing prefix-based mismatches such as an attacker-controlled domain like http://tx.fhir.org.attacker.com to match a legitimate configured URL like http://tx.fhir.org. The vulnerability is rated 7.4 on the CVSS v3.1 scale (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N) and maps to CWE-346.
A remote attacker without privileges can exploit this by registering a domain that prefixes a configured server URL. When an HTTP client follows a redirect to the attacker's domain, the flawed matching causes the dispatch of sensitive authentication credentials, including Bearer tokens, Basic auth credentials, or API keys, to the attacker-controlled endpoint. Exploitation requires high attack complexity, typically involving control over redirects or user interaction to trigger the client-side request.
The vulnerability has been patched in HAPI FHIR version 6.9.4. Additional details are available in the GitHub security advisory at https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-fgv2-4q4g-wc35.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-17524
Vulnerability Data
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.,…
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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.
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement directly requires validating the source of data before allowing transmission or receipt.
Device identification and authentication mandates verifying the source before establishing connections.
Session authenticity mechanisms require validation that communications originate from the expected party.
Boundary protection at interfaces enforces checks on the origin of incoming communications.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure coding practices include implementing proper origin validation to prevent spoofing.
Hardening callouts derived
DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.
- No fine-grained STIG row for CWE-346, a class-level weakness, and none of its children carries one either.