XXE in Hapifhir Hl7 Fhir Core
CVE-2026-55471
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.
Vulnerability class: XXE (XML External Entity)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.006 (45.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Hapifhir Hl7 Fhir Core
- Hapifhir Org.hl7.fhir.core — versions < 6.9.10
Weakness classification (CWE)
References
- github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2f55-g35j-5jmf (Exploit, Third Party Advisory)
- github.com/hapifhir/org.hl7.fhir.core/commit/01ca2ecdefec9b33204d2495fe78af8c0d… (Patch)
- github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.10 (Release Notes)
Frequently asked questions
- What is CVE-2026-55471?
- CVE-2026-55471 is a critical-severity vulnerability in Hapifhir Hl7 Fhir Core, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 9.1/10. Published 2026-07-08.
- How severe is CVE-2026-55471?
- Critical severity. CVSS v3 base score is 9.1 out of 10.