CVE-2026-34361
Hapifhir Hl7 Fhir Core ≤ 6.9.4
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:NSummary
CVE-2026-34361 is a critical-severity Files or Directories Accessible to External Parties (CWE-552) vulnerability in Hapifhir Hl7 Fhir Core. Its CVSS base score is 9.3 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 22th 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-3 (Access Enforcement) and AC-6 (Least Privilege) — 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-2026-34361 is a high-severity vulnerability in HAPI FHIR, a Java-based implementation of the HL7 FHIR standard for healthcare interoperability. Versions prior to 6.9.4 expose an unauthenticated "/loadIG" endpoint in the FHIR Validator HTTP service, which makes outbound HTTP requests to attacker-controlled URLs. This issue is compounded by a flaw in the credential provider function ManagedWebAccessUtils.getServer(), which performs insecure startsWith() URL prefix matching, allowing attackers to steal authentication tokens such as Bearer tokens, Basic auth credentials, or API keys configured for legitimate FHIR servers. The vulnerability is rated 9.3 on the CVSS 3.1 scale (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N) and maps to CWE-552 (Files or Directories Accessible to External Parties).
Any unauthenticated remote attacker can exploit this vulnerability over the network with low complexity and no user interaction required. By registering a malicious domain that prefix-matches a target organization's configured FHIR server URL, the attacker tricks the "/loadIG" endpoint into fetching resources from their server. During this process, the flawed credential matching logic applies and leaks valid authentication tokens intended for authorized FHIR servers, potentially enabling further unauthorized access to sensitive healthcare data.
The vulnerability has been patched in HAPI FHIR version 6.9.4. Additional mitigation details and technical analysis are available in the GitHub security advisory at https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-vr79-8m62-wh98.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-17528
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 5 hardening rules · 2 OS baselines
V8.4.2
Mitigating Controls (NIST 800-53 r5) AI
AC-3 directly enforces authorization checks on access to files and directories, stopping unauthorized external exposure.
AC-6 limits granted privileges, reducing the chance that files or directories become reachable by external parties.
AC-4 enforces information flow rules that can block unauthorized external access to files or directories.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Enforcing least-privilege permissions and authorization policies directly prevents unauthorized file/directory exposure.
Logical segmentation and access protections stop external parties from reaching files that should remain internal.
Data-at-rest protections such as encryption or ACLs reduce the impact of unintended file exposure.
Hardened configuration baselines commonly include file-system permission settings that limit external access.
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.
By tracing and retrieving all copies of information stored on endpoint and portable devices, the control reduces the likelihood that files remain accessible outside the organization’s security perimeter.
Labeling information according to its sensitivity and specifying corresponding protection measures makes it less probable that files or directories containing sensitive content will be left accessible to external parties.
Including asset location and ownership in the inventory, combined with secure disposal procedures, decreases the chance that files or directories remain accessible to external parties after they should have been removed or restricted.
Solid perimeters and locked external access points stop files, devices, or directories containing sensitive data from being reachable by external parties who could otherwise walk in or break in.
Authorizing and logging the removal of storage media, disabling unused ports, and monitoring transfers limit the exposure of files or directories to external parties outside the organization’s controlled environment.
Segregating delivery/loading zones and controlling external doors prevents external parties from reaching directories or resources that should remain inaccessible.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248579 OL 8 must restrict access to the kernel message buffer. prevents CWE-552
- V-248597 There must be no "shosts.equiv" files on the OL 8 operating system. prevents CWE-552