CVE-2026-62296

HAPI FHIR: XHTML narrative parser unbounded recursion causes StackOverflow denial of service

Published Aug 7, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.11, XhtmlParser.java imposes no maximum element nesting depth, so a deeply nested text.div narrative triggers unbounded recursion between parseElementInner() and parseElement(), raising a StackOverflowError. An attacker who can submit FHIR resources containing such narratives can thus crash a parsing or validation worker thread, affecting validator services and any application that parses attacker-supplied FHIR JSON or XML. This issue is fixed in version 6.9.11.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Hapifhir
Hapifhir hl7 Fhir Core
Vendors & Products Hapifhir
Hapifhir hl7 Fhir Core
Type Values Removed Values Added
Description HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.11, XhtmlParser.java imposes no maximum element nesting depth, so a deeply nested text.div narrative triggers unbounded recursion between parseElementInner() and parseElement(), raising a StackOverflowError. An attacker who can submit FHIR resources containing such narratives can thus crash a parsing or validation worker thread, affecting validator services and any application that parses attacker-supplied FHIR JSON or XML. This issue is fixed in version 6.9.11.
Title HAPI FHIR: XHTML narrative parser unbounded recursion causes StackOverflow denial of service
Weaknesses CWE-20
CWE-400
CWE-674
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 10, 2026, 1:29 PM
Reserved
Jul 13, 2026, 6:37 PM
Status
Deferred
Published
Aug 7, 2026, 8:16 PM
Modified
Sep 9, 2026, 9:02 PM