CVE-2026-55471
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedHAPI 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceHAPI FHIR's XsltUtilities saxonTransform() methods instantiate a bare Saxon TransformerFactoryImpl without restricting ACCESS_EXTERNAL_DTD and ACCESS_EXTERNAL_STYLESHEET, enabling XXE injection when processing attacker-controlled XML. This allows local file disclosure, blind XXE for out-of-band data exfiltration, and SSRF to internal network resources.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 6.9.10CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify HAPI FHIR installationSearch for HAPI FHIR libraries in your project dependencies (Maven pom.xml, Gradle build files, or JAR files in the classpath). Look for artifacts with groupId 'ca.uhn.hapi.fhir' such as 'hapi-fhir-base', 'hapi-fhir-structures-dstu2', 'hapi-fhir-structures-r4', or 'hapi-fhir-core'.Affected if HAPI FHIR library is present with version < 6.9.10
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Locate XsltUtilities classSearch for the XsltUtilities class in your codebase or dependencies. Check if Saxon transformation is performed via saxonTransform() methods. Look for imports of 'ca.uhn.hapi_fhir.xslt.XsltUtilities' or usage of Saxon TransformerFactory.Affected if Code uses XsltUtilities.saxonTransform() methods to process XML with untrusted input
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Verify XML input sourceAudit XML processing paths that feed into XsltUtilities. Determine whether XML data originates from external/untrusted sources (user uploads, API requests, external system integrations).Affected if XML processed by XsltUtilities can come from untrusted or attacker-controlled sources
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Check Saxon security configurationInspect the TransformerFactory initialization in XsltUtilities or related code. Look for explicit setting of security properties: setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, ""), setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, ""), or similar restrictions.Affected if No ACCESS_EXTERNAL_DTD or ACCESS_EXTERNAL_STYLESHEET restrictions are configured on the Saxon TransformerFactory
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Review XML parser configurationCheck if the application-level XML parsers (DocumentBuilder, SAXParser) have XXE protections enabled (DFA_DISABLE, II_CHILD_UPPER_EXTERNAL_ENTITY_RESOLVER disabled). Also verify network access controls for SSRF prevention.Affected if No XXE protections at the application boundary and no network segmentation for internal resources
Your environment is affected if you run any HAPI FHIR version below 6.9.10 that uses XsltUtilities.saxonTransform() to process XML from untrusted sources without Saxon security restrictions in place.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped6.9.10
Upgrade to HAPI FHIR version 6.9.10 or later which adds the required external access restrictions. If immediate upgrade is not feasible, ensure XML input is from trusted sources only or implement XML parser hardening at the application boundary.
org.hl7.fhir.core version 6.9.10
- Identify all Java applications that depend on org.hl7.fhir.core version earlier than 6.9.10
- Locate the Maven pom.xml, Gradle build.gradle, or other dependency management files that declare the org.hl7.fhir.core dependency
- Update the version specification for org.hl7.fhir.core from the current version (e.g., 6.9.9 or earlier) to version 6.9.10 or later (e.g., 6.9.10)
- Run Maven dependency:tree or Gradle dependencies to confirm the updated version is resolved
- Rebuild the application with the updated dependency
- Redeploy the rebuilt application to all affected environments
- Verify the fix by reviewing that the patched code at commit 01ca2ecdefec9b33204d2495fe78af8c0dc52298 is included in the runtime
- Optionally, test that XML transformations with untrusted input no longer allow XXE by attempting a controlled XXE payload
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-55471 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-55471 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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