Vulnerability · Published Jul 17, 2026 · Assigned by GitHub_M
CVE-2026-49485HAPI FHIR: ReDoS via FHIRPath matches()/replaceMatches() in FHIR Validator HTTP Endpoint
High 7.5
In plain English
A high-severity regular-expression denial of service in org.hl7.fhir.core from hapifhir. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.dstu2 | 6.9.9 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.dstu2 | 6.9.4.2 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.dstu2016may | 6.9.9 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.dstu2016may | 6.9.4.2 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.dstu3 | 6.9.9 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.dstu3 | 6.9.4.2 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.r4 | 6.9.9 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.r4 | 6.9.4.2 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.r4b | 6.9.9 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.r4b | 6.9.4.2 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.r5 | 6.9.9 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.r5 | 6.9.4.2 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.validation | 6.9.4.2 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.validation | 6.9.9 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli | 6.9.9 | GHSA-7cmj-v6x8-frvv |
| Maven | ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli | 6.9.4.2 | GHSA-7cmj-v6x8-frvv |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| hapifhir | org.hl7.fhir.core | < 6.9.4.2>= 6.9.5, < 6.9.9 |
Weakness: CWE-1333, CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-7cmj-v6x8-frvv x_refsource_CONFIRM
- https://github.com/hapifhir/org.hl7.fhir.core/pull/2463 x_refsource_MISC
- https://github.com/hapifhir/org.hl7.fhir.core/commit/109c88837c032ef399b2eb87ddde86692065cf41 x_refsource_MISC
- https://github.com/hapifhir/org.hl7.fhir.core/commit/e08982d2b6f6dcd6c670a762d9cf999179fbe4ed x_refsource_MISC
- https://github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.4.2 x_refsource_MISC
- https://github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.9 x_refsource_MISC