# CVE-2026-124464: OpenEMR before 8.4.0 FHIR Patient Compartment Bypass via QuestionnaireResponse

Status: published. Published: 2026-11-08. Updated: 2026-11-10.

OpenEMR before 8.4.0 contains an authorization bypass vulnerability that allows patient-scoped SMART tokens to read other patients' questionnaire responses because FhirQuestionnaireResponseService does not implement IPatientCompartmentResourceService. Attackers holding a patient/QuestionnaireResponse.rs token can request responses by uuid or list the unfiltered bundle to obtain cross-patient clinical assessment answers.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- openemr / openemr: ≥ 0; < 8.4.0 (affected, semver); 8.4.0 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 7.1 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N; source: CNA: VulnCheck

- CVSS 4.0: 7.1 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.27% as of 2026-11-10; percentile 19.89%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-639

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/openemr/openemr/security/advisories/GHSA-fmmr-p679-97fq (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/openemr-before-8.4.0-fhir-patient-compartment-bypass-via-questionnaireresponse (CNA: VulnCheck; third-party-advisory)

- https://github.com/openemr/openemr/security/advisories/GHSA-fmmr-p679-97fq (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/openemr-before-8.4.0-fhir-patient-compartment-bypass-via-questionnaireresponse (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-124464; retrieved 2026-11-10; source updated 2026-11-10

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-124464; retrieved 2026-11-08; source updated 2026-11-08

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-124464; retrieved 2026-11-10; source updated Not reported

Revision: 022731608af5595dc93b189616c32fe8af6cd902151e84defd247cca0fea43ef

Canonical: https://y2.dev/cve/CVE-2026-124464

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