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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
hapifhir org.hl7.fhir.core affected
Version Status Constraints
< 6.9.11 affected —
hapifhir ca.uhn.hapi.fhir:org.hl7.fhir.r5 affected
Version Status Constraints
< 6.9.11 affected —
hapifhir ca.uhn.hapi.fhir:org.hl7.fhir.utilities affected
Version Status Constraints
< 6.9.11 affected —
hapifhir ca.uhn.hapi.fhir:org.hl7.fhir.validation affected
Version Status Constraints
< 6.9.11 affected —
hapifhir ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli affected
Version Status Constraints
< 6.9.11 affected —

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Project Subscriptions

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/hapifhir/org.hl7.fhir.core/commit/396f447500407693d6ae1e64db59782862ca7506 cve-icon
https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2cq7-hg49-56gc cve-icon
History

Fri, 07 Aug 2026 20:00:00 +0000

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, 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.
Title HAPI FHIR: JSON utility 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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-07T19:36:31.274Z

Reserved: 2026-07-13T18:37:08.488Z

Link: CVE-2026-62295

cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

Updated: 2026-08-07T21:30:18Z

Weaknesses