CVE-2026-55470

HAPI FHIR: DSTU2 FHIRPathEngine.matches() missing RegexTimeout protection allows ReDoS

Published Jul 8, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.10, the fix for CVE-2026-45367 incompletely patched the DSTU2 module, leaving FHIRPathEngine.matches() in org.hl7.fhir.dstu2/utils/FHIRPathEngine.java to call raw String.matches(sw) without RegexTimeout protection while replaceMatches() was updated, allowing an unauthenticated attacker to trigger catastrophic regex backtracking and exhaust server CPU. This issue is fixed in version 6.9.10.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-fxj4-p9xp-37v5 HAPI FHIR: Incomplete fix for CVE-2026-45367: DSTU2 FHIRPathEngine.matches() missing RegexTimeout protection allows ReDoS
History
Type Values Removed Values Added
First Time appeared Hapifhir
Hapifhir hl7 Fhir Core
Vendors & Products Hapifhir
Hapifhir hl7 Fhir Core
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.10, the fix for CVE-2026-45367 incompletely patched the DSTU2 module, leaving FHIRPathEngine.matches() in org.hl7.fhir.dstu2/utils/FHIRPathEngine.java to call raw String.matches(sw) without RegexTimeout protection while replaceMatches() was updated, allowing an unauthenticated attacker to trigger catastrophic regex backtracking and exhaust server CPU. This issue is fixed in version 6.9.10.
Title HAPI FHIR: DSTU2 FHIRPathEngine.matches() missing RegexTimeout protection allows ReDoS
Weaknesses CWE-1333
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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 9, 2026, 12:59 PM
Reserved
Jun 16, 2026, 10:10 PM
Status
Analyzed
Published
Jul 8, 2026, 10:17 PM
Modified
Oct 25, 2026, 5:10 PM
Severity
Important
Public date
Jul 8, 2026, 9:27 PM