CVE-2026-45367 HAPI FHIR: ReDoS via FHIRPath matches()/replaceMatches() in FHIR Validator HTTP Endpoint
Attackers can cause denial of service in HAPI FHIR applications by submitting malicious regular expressions to FHIRPath validation endpoints.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-45367?
CVE-2026-45367 is a high-severity denial of service vulnerability in hapifhir org.hl7.fhir.core, published on 16 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-1333
Which versions are affected by CVE-2026-45367?
16 open source packages ship an affected version, including ca.uhn.hapi.fhir:org.hl7.fhir.dstu2, ca.uhn.hapi.fhir:org.hl7.fhir.dstu2016may and ca.uhn.hapi.fhir:org.hl7.fhir.dstu3.
| Package | Affected | Fixed in |
|---|---|---|
ca.uhn.hapi.fhir:org.hl7.fhir.dstu2 Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.dstu2 Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.dstu2016may Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.dstu2016may Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.dstu3 Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.dstu3 Maven | All versions | 6.9.7 |
10 more packages
ca.uhn.hapi.fhir:org.hl7.fhir.r4 Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.r4 Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.r4b Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.r4b Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.r5 Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.r5 Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.validation Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.validation Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli Maven | All versions | 6.9.7 |
ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli Maven | All versions | 6.9.7 |
How do I fix CVE-2026-45367?
Upgrade ca.uhn.hapi.fhir:org.hl7.fhir.dstu2 to 6.9.7 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-45367 being exploited?
There is no known exploitation of CVE-2026-45367 in the wild and no public exploit code.
Sources
Also known as GHSA-3653-68v6-rq57, ROOT-APP-MAVEN-CVE-2026-45367.