CVE-2026-62296
No fix known EPSS <1%CVSS 7.5
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.
Products: hapifhir org.hl7.fhir.core, hapifhir ca.uhn.hapi.fhir:org.hl7.fhir.r5, hapifhir ca.uhn.hapi.fhir:org.hl7.fhir.utilities, hapifhir ca.uhn.hapi.fhir:org.hl7.fhir.validation, hapifhir ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli