Description
HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to 6.9.7, the FHIRPathEngine implementation passes user-controlled regular expressions from matches(), matchesFull(), and replaceMatches() to Java regex operations without effective timeouts, allowing catastrophic backtracking and denial of service. This issue is fixed in version 6.9.7.
References6
- github.com/hapifhir/org.hl7.fhir.core/commit/275d015c680ce9f90c…
- github.com/hapifhir/org.hl7.fhir.core/commit/e08982d2b6f6dcd6c6…
- github.com/hapifhir/org.hl7.fhir.core/pull/2403
- github.com/hapifhir/org.hl7.fhir.core/pull/2463
- github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.7
- github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-…
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 53 · as of 15 November 2026
- CWE
- CWE-1333
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.