CVE-2026-34360
An unauthenticated attacker with network access to the validator can probe internal network services, cloud metadata endpoints, and map network topology through error-based information leakage.
Does this matter?
Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own.
Description
HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to version 6.9.4, the /loadIG HTTP endpoint in the FHIR Validator HTTP service accepts a user-supplied URL via JSON body and makes server-side HTTP requests to it without any hostname, scheme, or domain validation. An unauthenticated attacker with network access to the validator can probe internal network services, cloud metadata endpoints, and map network topology through error-based information leakage. With explore=true (the default for this code path), each request triggers multiple outbound HTTP calls, amplifying reconnaissance capability. This issue has been patched in version 6.9.4.
- CVSS 3.1
- 5.8 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
- EPSS
- 0.24% probability · 15th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-918
- Affected
- hapifhir/hl7 fhir core
- Source
- security-advisories@github.com
References
- https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-3ww8-jw56-9f5hExploit, Vendor Advisory
- https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-3ww8-jw56-9f5hExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.