CVE-2026-55471
HAPI FHIR: XXE in XsltUtilities.saxonTransform via unhardened Saxon TransformerFactory
Description
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.
INFO
Published Date :
July 8, 2026, 10:17 p.m.
Last Modified :
July 16, 2026, 4:32 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update HAPI FHIR to version 6.9.10.
- Apply security patches for the affected versions.
- Restrict external DTD and stylesheet access.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-55471.
| URL | Resource |
|---|---|
| https://github.com/hapifhir/org.hl7.fhir.core/commit/01ca2ecdefec9b33204d2495fe78af8c0dc52298 | Patch |
| https://github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.10 | Release Notes |
| https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2f55-g35j-5jmf | Exploit Third Party Advisory |
| https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2f55-g35j-5jmf | Exploit Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-55471 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-55471
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-55471 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-55471 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 16, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:hapifhir:hl7_fhir_core:*:*:*:*:*:*:*:* versions up to (excluding) 6.9.10 Added Reference Type GitHub, Inc.: https://github.com/hapifhir/org.hl7.fhir.core/commit/01ca2ecdefec9b33204d2495fe78af8c0dc52298 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.10 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2f55-g35j-5jmf Types: Exploit, Third Party Advisory Added Reference Type CISA-ADP: https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2f55-g35j-5jmf Types: Exploit, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 09, 2026
Action Type Old Value New Value Added Reference https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2f55-g35j-5jmf Added SSVC {'id': 'CVE-2026-55471', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-09T13:26:09.323278Z'} -
New CVE Received by [email protected]
Jul. 08, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'hapifhir', 'product': 'org.hl7.fhir.core', 'versions': [{'status': 'affected', 'version': '< 6.9.10'}]}] Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-611 Added Reference https://github.com/hapifhir/org.hl7.fhir.core/commit/01ca2ecdefec9b33204d2495fe78af8c0dc52298 Added Reference https://github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.10 Added Reference https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2f55-g35j-5jmf