CVE-2026-55471
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk23th percentile - higher than 23% of all known CVEs
Summary
A vulnerability in HAPI FHIR before version 6.9.10 allows XML External Entity (XXE) injection via the saxonTransform function in XsltUtilities. Missing ACCESS_EXTERNAL_DTD and ACCESS_EXTERNAL_STYLESHEET restrictions enable an attacker to read local files, perform blind XXE, and SSRF to arbitrary URLs.
Risk Assessment
The organization risks exposure of sensitive local files and potential SSRF attacks against internal network resources. This could compromise data confidentiality and system integrity.
Recommendation
Upgrade HAPI FHIR to version 6.9.10 or later immediately. If upgrading is not feasible, restrict access to XML transformation functions and apply firewall rules to block malicious requests.
Original NVD description (English source)
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.