Description

HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.9 and 6.9.4.2, all implementations of FHIRPathEngine accept arbitrary FHIRPath expressions and evaluate them without input validation, and the FHIRPath functions matches(), matchesFull(), and replaceMatches() pass user-controlled regular expressions to Java's Pattern.compile() and String.replaceAll() through an incomplete timeout utility. An attacker can send a resource containing an evil regex pattern that causes catastrophic backtracking, exhausting CPU resources and causing denial of service in the FHIR Validator HTTP endpoint and affected org.hl7.fhir.* modules. This issue is fixed in versions 6.9.9 and 6.9.4.2.

Severity (CVSS)

Base score7.5
SeverityHigh
VersionCVSS 3.1
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Provided byCNA

Weaknesses

  • CWE-1333 — CWE-1333: Inefficient Regular Expression Complexity
  • CWE-400 — CWE-400: Uncontrolled Resource Consumption

Affected products

VendorProductVersions
hapifhirorg.hl7.fhir.core< 6.9.4.2; >= 6.9.5, < 6.9.9

References

Authoritative sources

This page is a snapshot. For the latest enrichment and updates, view the record on CVE.org or the NVD.

Generated from the official CVE List on 18 Jul 2026 07:00 UTC.