Resource exhaustion in Hapifhir Org.hl7.fhir.core
CVE-2026-49485
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.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.007 (50.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Hapifhir Org.hl7.fhir.core — versions < 6.9.4.2, >= 6.9.5, < 6.9.9
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-49485?
- CVE-2026-49485 is a high-severity vulnerability in Hapifhir Org.hl7.fhir.core, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-07-17.
- How severe is CVE-2026-49485?
- High severity. CVSS v3 base score is 7.5 out of 10.