CVE intelligence and bounded remediation

CVE-2026-55471 — HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java

Critical CVSS 9.1

HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.10, org.hl7.fhir.utilities.XsltUtilities saxonTransform(...) overloads instantiated a bare net.sf.saxon.TransformerFactoryImpl() without ACCESS_EXTERNAL_DTD or ACCESS_EXTERNAL_STYLESHEET restrictions, allowing an attacker who controls or can tamper with transformed XML to trigger XML External Entity injection for local file disclosure and blind XXE or SSRF to arbitrary URLs reachable from the host. This issue is fixed in version 6.9.10.

Severity
Critical
CVSS
9.1 (3.1)
Published
2026-07-08
CISA KEV
Not currently listed
Ecosystem
java/maven
Weaknesses
CWE-611

Affected products

  • hapifhir / hl7_fhir_core

Matched remediation archetype

XML external entity and unsafe XML processing

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Check exposure

  • Inventory XML parsers used by APIs, file imports, office or image formats, identity protocols, feeds, and background jobs.
  • Determine whether document type declarations, external entities, XInclude, schemas, or network resolvers are enabled.
  • Map parser filesystem and network access and the sensitivity of documents it processes.

Remediate safely

  • Configure each parser to reject document type declarations and disable external entity, XInclude, and network resolution features.
  • Prefer a data format or hardened parser that does not support external resolution, and apply input size and depth limits.
  • Update affected XML libraries and centralize secure parser construction so callers cannot silently override it.

Authoritative sources

Complete CVE record and remediation plan

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