---
id: CVE-2026-81875
title: >-
  HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare
  interoperability in Java
summary: >-
  HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare
  interoperability in Java. Prior to version 6.9.12, SHCParser in
  org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/SHCParser.java can
  consume attacker…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-20
  - CWE-400
  - CWE-409
vendor: hapifhir
product: org.hl7.fhir.core
affected:
  - org.hl7.fhir.core < 6.9.12
published: '2026-09-16'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T17:16:48.207'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-81875'
references:
  - url: >-
      https://github.com/hapifhir/org.hl7.fhir.core/commit/fbb94216e0ad21ded75be77e5e20242ba194e83f
    label: security-advisories@github.com
  - url: 'https://github.com/hapifhir/org.hl7.fhir.core/pull/2493'
    label: security-advisories@github.com
  - url: 'https://github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.11'
    label: security-advisories@github.com
  - url: 'https://github.com/hapifhir/org.hl7.fhir.core/releases/tag/6.9.12'
    label: security-advisories@github.com
  - url: >-
      https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-3w98-rrpr-fprr
    label: security-advisories@github.com
  - url: >-
      https://github.com/hapifhir/org.hl7.fhir.core/security/advisories/GHSA-3w98-rrpr-fprr
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-81875'
  - url: 'https://github.com/advisories/GHSA-3w98-rrpr-fprr'
tags:
  - nvd
  - cve.org
  - exploit-available
  - ghsa
  - maven
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-17T16:14:08.266567Z'
ingestedAt: '2026-09-16T19:02:30.725Z'
aliases:
  - GHSA-3w98-rrpr-fprr
ecosystem: maven
patched:
  - 'ca.uhn.hapi.fhir:org.hl7.fhir.r5 6.9.12'
  - 'ca.uhn.hapi.fhir:org.hl7.fhir.validation 6.9.12'
epss: 0.0063
epssPercentile: 0.47953
---

## Overview

HAPI FHIR is a complete implementation of the HL7 FHIR standard for healthcare interoperability in Java. Prior to version 6.9.12, SHCParser in org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/SHCParser.java can consume attacker-controlled Smart Health Card JWT content whose header contains zip: "DEF" and whose small raw-DEFLATE payload expands to a very large value. SHCParser.decodeJWT() passes the decoded payload to SHCParser.inflate(), which accumulates all decompressed bytes in a ByteArrayOutputStream without an output-size limit before JSON parsing, and SHCParser.decompress() contains the same unbounded pattern. An application or validator service that accepts attacker-supplied SHC content can therefore suffer excessive heap allocation, severe garbage-collection pressure, request failure, process instability, or process termination. This issue is fixed in version 6.9.12.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-81875)

Affected packages:

- `ca.uhn.hapi.fhir:org.hl7.fhir.r5 <= 6.9.11`
- `ca.uhn.hapi.fhir:org.hl7.fhir.validation <= 6.9.11`
- `ca.uhn.hapi.fhir:org.hl7.fhir.validation.cli <= 5.0.0`

Patched in:

- `ca.uhn.hapi.fhir:org.hl7.fhir.r5 6.9.12`
- `ca.uhn.hapi.fhir:org.hl7.fhir.validation 6.9.12`

Source: https://github.com/advisories/GHSA-3w98-rrpr-fprr