# CVE-2026-124464: OpenEMR FHIR Patient Compartment bypass in QuestionnaireResponse

Source: https://junglewise.ai/threats/cve-2026-124464-openemr-before-8-4-0-contains-an-authorization-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-08. Updated: 2026-11-08  
License: CC BY 4.0 with a link back

CVE-2026-124464 · Severity: medium · CVSS 6.5 · Published 2026-11-08

OpenEMR is an open-source electronic health record (EHR) system that manages patient medical data. A flaw in its FHIR API implementation allows a patient holding a valid SMART authentication token to read any other patient's questionnaire responses, such as mental health screening results or social determinant surveys. An attacker with a legitimate patient account can access sensitive clinical assessment data belonging to other patients by exploiting missing access controls.

Technologies: [OpenEMR](https://junglewise.ai/threats/technologies/openemr-openemr). Vendors: [OpenEMR](https://junglewise.ai/threats/vendors/openemr).

## Quick answers

**Is CVE-2026-124464 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-124464 being exploited in the wild.

**How severe is CVE-2026-124464?** Medium severity, with a CVSS score of 6.5, published 8 November 2026.

**Which products and versions are affected?** OpenEMR before 8.4.0.

**Is there a fix for CVE-2026-124464?** Yes: fixed in 8.4.0. Until then: Restrict network access to the FHIR API endpoints to trusted networks or implement additional API gateway controls until upgrade; audit FHIR API logs for cross-patient QuestionnaireResponse requests by patient-scoped tokens. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-124464 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-124464?** Check whether you run OpenEMR at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 8.4.0

Restrict network access to the FHIR API endpoints to trusted networks or implement additional API gateway controls until upgrade; audit FHIR API logs for cross-patient QuestionnaireResponse requests by patient-scoped tokens.

## Technical details

The FhirQuestionnaireResponseService class handles patient questionnaire responses but does not implement IPatientCompartmentResourceService, causing the FHIR Patient Compartment enforcement gate in FhirServiceBase::getOne() to skip the per-patient UUID binding. This allows an attacker with a patient-scoped SMART token (patient/QuestionnaireResponse.rs) to bypass patient isolation by directly requesting other patients' responses via UUID or by enumerating the unfiltered response bundle. The vulnerability requires network access and a valid patient-launch token, with no user interaction needed; the underlying data access layer applies no patient-filtering WHERE clause.

## Affected products

- OpenEMR OpenEMR before 8.4.0

## Timeline

- 2026-09-13: advisory: GitHub security advisory GHSA-fmmr-p679-97fq published
- 2026-11-08: disclosed: CVE-2026-124464 published

## References

- [https://github.com/openemr/openemr/security/advisories/GHSA-fmmr-p679-97fq](https://github.com/openemr/openemr/security/advisories/GHSA-fmmr-p679-97fq)
- [https://www.vulncheck.com/advisories/openemr-before-8.4.0-fhir-patient-compartment-bypass-via-questionnaireresponse](https://www.vulncheck.com/advisories/openemr-before-8.4.0-fhir-patient-compartment-bypass-via-questionnaireresponse)

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