CVE-2026-62296
HAPI FHIR: XHTML narrative 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, 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.
INFO
Published Date :
Aug. 7, 2026, 8:16 p.m.
Last Modified :
Aug. 7, 2026, 8:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-62296
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update HAPI FHIR to version 6.9.11 or later.
- Apply relevant patches if updating is not immediately possible.
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-2026-62296.
| URL | Resource |
|---|---|
| https://github.com/hapifhir/org.hl7.fhir.core/commit/396f447500407693d6ae1e64db59782862ca7506 | |
| https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-5v24-q6x8-hc38 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-62296 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-2026-62296
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-2026-62296 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-62296 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.
-
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, 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. 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-5v24-q6x8-hc38