CVE-2026-55471Public exploitNetwork attack vector

File disclosure and SSRF via unrestricted external entities

Published Jul 8, 2026 · Updated Jul 8, 2026

XXE in HAPI FHIR org.hl7.fhir.core before 6.9.10 allows remote attackers to read local files or make host-side requests. XsltUtilities.saxonTransform creates bare Saxon TransformerFactoryImpl instances that resolve external entities, DTDs, and stylesheets from untrusted XML. Reachability requires attacker-controlled or tampered XML to reach a saxonTransform overload; exposure is limited to JVM-readable files and URLs reachable from the host.

CVSS severity9.1
Critical
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

XXE in HAPI FHIR org.hl7.fhir.core before 6.9.10 allows remote attackers to read local files or make host-side requests. XsltUtilities.saxonTransform creates bare Saxon TransformerFactoryImpl instances that resolve external entities, DTDs, and stylesheets from untrusted XML. Reachability requires attacker-controlled or tampered XML to reach a saxonTransform overload; exposure is limited to JVM-readable files and URLs reachable from the host.

The record

CVE
CVE-2026-55471
Published
Jul 8, 2026
Updated
Jul 8, 2026
Vendor
HAPI FHIR
Product
org.hl7.fhir.core
Classifications
CWE-611, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 6.9.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

HAPI FHIR · org.hl7.fhir.coreversion=< 6.9.10

Published CVSS scores

9.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
8.7GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
T1005Data from Local System

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo