---
id: CVE-2026-62295
title: >-
  HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare
  interoperability in Java
summary: >-
  HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare
  interoperability in Java. Prior to 6.9.11, the JSON utility parser in
  org.hl7.fhir.utilities.json.parser.JsonParser enforces no maximum nesting
  depth for arra…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-20
  - CWE-400
  - CWE-674
vendor: hapifhir
product: org.hl7.fhir.core
affected:
  - org.hl7.fhir.core < 6.9.11
  - 'ca.uhn.hapi.fhir:org.hl7.fhir.r5 < 6.9.11'
  - 'ca.uhn.hapi.fhir:org.hl7.fhir.utilities < 6.9.11'
  - 'ca.uhn.hapi.fhir:org.hl7.fhir.validation < 6.9.11'
  - 'ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli < 6.9.11'
published: '2026-08-07'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:02:22.660'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-62295'
references:
  - url: >-
      https://github.com/hapifhir/org.hl7.fhir.core/commit/396f447500407693d6ae1e64db59782862ca7506
    label: security-advisories@github.com
  - url: >-
      https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2cq7-hg49-56gc
    label: security-advisories@github.com
  - url: >-
      https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2cq7-hg49-56gc
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-08-13T18:38:14.529863Z'
ingestedAt: '2026-09-14T04:28:46.887Z'
epss: 0.00488
epssPercentile: 0.39416
---

## Overview

HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.11, the JSON utility parser in org.hl7.fhir.utilities.json.parser.JsonParser enforces no maximum nesting depth for arrays or objects. As a result, a small but deeply nested, syntactically valid FHIR JSON document can trigger unbounded readArray() or readObject() recursion, raising a StackOverflowError before structural validation runs. An attacker who can submit JSON resources for validation can thus crash the request thread, and services that do not isolate StackOverflowError safely may experience worker loss or process instability — a denial-of-service condition. This issue is fixed in version 6.9.11.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.