org.hl7.fhir.core: ReDoS via FHIRPath matches()/replaceMatches() in FHIR Validator HTTP Endpoint

All implementations of FHIRPathEngine accept arbitrary FHIRPath expressions and evaluate them without input validation. The utility intended to secure this evaluation did so incorrectly, and did not fully cover all places in which evaluation was being done. An attacker can send a resource...

CVE-2026-55470

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.matchessw...

HAPI FHIR: Incomplete fix for CVE-2026-45367: DSTU2 FHIRPathEngine.matches() missing RegexTimeout protection allows ReDoS

The fix for CVE-2026-45367 added RegexTimeout protection to the matches function in DSTU2016MAY, DSTU3, R4, R4B, and R5, but the DSTU2 module was incompletely patched. In org.hl7.fhir.dstu2, replaceMatches was updated while matches at line 2462 still calls the raw String.matchessw without any...