CVE-2026-62295
HAPI FHIR: JSON utility parser unbounded recursion causes StackOverflow denial of service
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.
INFO
Published Date :
Aug. 7, 2026, 8:16 p.m.
Last Modified :
Aug. 13, 2026, 7:17 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 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update HAPI FHIR to version 6.9.11.
- Ensure parser does not allow deep nesting.
- Monitor for process instability.
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-2026-62295.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-62295 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-2026-62295
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-2026-62295 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-62295 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.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 13, 2026
Action Type Old Value New Value Added Reference https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2cq7-hg49-56gc Added SSVC {'id': 'CVE-2026-62295', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-13T18:38:14.529863Z'} -
New CVE Received by [email protected]
Aug. 07, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'hapifhir', 'product': 'org.hl7.fhir.core', 'versions': [{'status': 'affected', 'version': '< 6.9.11'}]}, {'vendor': 'hapifhir', 'product': 'ca.uhn.hapi.fhir:org.hl7.fhir.r5', 'versions': [{'status': 'affected', 'version': '< 6.9.11'}]}, {'vendor': 'hapifhir', 'product': 'ca.uhn.hapi.fhir:org.hl7.fhir.utilities', 'versions': [{'status': 'affected', 'version': '< 6.9.11'}]}, {'vendor': 'hapifhir', 'product': 'ca.uhn.hapi.fhir:org.hl7.fhir.validation', 'versions': [{'status': 'affected', 'version': '< 6.9.11'}]}, {'vendor': 'hapifhir', 'product': 'ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli', 'versions': [{'status': 'affected', 'version': '< 6.9.11'}]}] 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-20 Added CWE CWE-400 Added CWE CWE-674 Added Reference https://github.com/hapifhir/org.hl7.fhir.core/commit/396f447500407693d6ae1e64db59782862ca7506 Added Reference https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-2cq7-hg49-56gc