TI-2026-44485 Aliases CVE-2026-62296

HAPI FHIR: XHTML narrative parser unbounded recursion causes StackOverflow denial of service

HIGH 72CWE-20Published 2026-08-07 · Updated 2026-08-10

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 1 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-400.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00488 42nd percentileScored 2026-11-07

Fix Partial org.hl7.fhir.core (hapifhir): 6.9.11ca.uhn.hapi.fhir:org.hl7.fhir.r5 (hapifhir): 6.9.11+3 more productsRed Hat: 1 advisoryRed Hat: 1 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
hapifhir	org.hl7.fhir.core	before 6.9.11	6.9.11	Patch available	CNA
hapifhir	ca.uhn.hapi.fhir:org.hl7.fhir.r5	before 6.9.11	6.9.11	Patch available	CNA
hapifhir	ca.uhn.hapi.fhir:org.hl7.fhir.utilities	before 6.9.11	6.9.11	Patch available	CNA
hapifhir	ca.uhn.hapi.fhir:org.hl7.fhir.validation	before 6.9.11	6.9.11	Patch available	CNA
hapifhir	ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli	before 6.9.11	6.9.11	Patch available	CNA

org.hl7.fhir.core Vendorhapifhir Affected before 6.9.11 Fixed in 6.9.11 Patch available CNA
ca.uhn.hapi.fhir:org.hl7.fhir.r5 Vendorhapifhir Affected before 6.9.11 Fixed in 6.9.11 Patch available CNA
ca.uhn.hapi.fhir:org.hl7.fhir.utilities Vendorhapifhir Affected before 6.9.11 Fixed in 6.9.11 Patch available CNA
ca.uhn.hapi.fhir:org.hl7.fhir.validation Vendorhapifhir Affected before 6.9.11 Fixed in 6.9.11 Patch available CNA
ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli Vendorhapifhir Affected before 6.9.11 Fixed in 6.9.11 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:hapifhir:hl7_fhir_core::::::::	—	—	hapifhir

cpe:2.3:a:hapifhir:hl7_fhir_core:*:*:*:*:*:*:*:* Versions — — ·hapifhir

Remediation

Fix · CNA org.hl7.fhir.core (hapifhir) Fixed in 6.9.11
Fix · CNA ca.uhn.hapi.fhir:org.hl7.fhir.r5 (hapifhir) Fixed in 6.9.11
Fix · CNA ca.uhn.hapi.fhir:org.hl7.fhir.utilities (hapifhir) Fixed in 6.9.11
Fix · CNA ca.uhn.hapi.fhir:org.hl7.fhir.validation (hapifhir) Fixed in 6.9.11
Fix · CNA ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli (hapifhir) Fixed in 6.9.11

Red Hat 1 advisory

RHSA-2026:54776 Released 2026-08-13 · Red Hat rating Important
Red Hat Build of Apache Camel 4.18 for Quarkus 3.33 update is now available (RHBQ 3.33.3.GA)
- Red Hat Build of Apache Camel 4.18 for Quarkus 3.33

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat build of Apache Camel 4 for Quarkus 3	Affected	No fix yet
Red Hat Build of Apache Camel 4.18 for Quarkus 3.33	Fixed	RHSA-2026:54776

Not affected: 1 product

Red Hat JBoss Enterprise Application Platform Expansion Pack

Timeline

2026-10-02 Threatist record created from CVE-2026-62296
2026-10-08 Affected versions changed · Red Hat
2026-10-12 Fix available: RHSA-2026:54776 · Red Hat
2026-10-12 Fix available: Red Hat Build of Apache Camel 4.18 for Quarkus 3.33 · Red Hat

References

Other 2

TI-2026-26647 HAPI FHIR: Unauthenticated SSRF via /loadIG Chains with startsWith() Credential Leak for Authentication Token Theft CVSS 3.1CRITICAL 9.3
TI-2026-40028 HAPI FHIR: XXE in XsltUtilities.saxonTransform via unhardened Saxon TransformerFactory CVSS 4.0HIGH 8.7
TI-2026-26645 HAPI FHIR: Authentication Credential Leakage via Improper URL Prefix Matching on HTTP Redirect in HAPI FHIR Core CVSS 3.1CRITICAL 9.1
TI-2026-56488 HAPI FHIR: SHCParser DEFLATE infinite loop causes denial of service CVSS 3.1HIGH 7.5
TI-2026-56487 HAPI FHIR: SHCParser unbounded DEFLATE decompression causes denial of service CVSS 3.1HIGH 7.5
TI-2026-44484 HAPI FHIR: JSON utility parser unbounded recursion causes StackOverflow denial of service CVSS 3.1HIGH 7.5

See all 17 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences