CVE-2026-124481

MEDIUM 6.5

OpenEMR before 8.4.0 Cross-Patient Payment Tampering via Rainforest Portal Payments

CVSS Score

6.5

EPSS Score

0.0%

EPSS Percentile

0th

OpenEMR before 8.4.0 contains an improper authorization vulnerability in Rainforest patient portal payments that trusts browser-supplied patientId, encounter, and amount values instead of deriving them from the portal session. Authenticated portal patients can tamper with JSON sent to portal_payment.rainforest.php so the payin.authorized webhook writes forged ar_activity credits to other patients' encounters exceeding the amount actually paid.

CWE	CWE-639
Vendor	openemr
Product	openemr
Published	Nov 8, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Affected Versions

openemr / openemr

0 < 8.4.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/openemr/openemr/security/advisories/GHSA-525m-fch5-vqqm vulncheck.com: https://www.vulncheck.com/advisories/openemr-before-8.4.0-cross-patient-payment-tampering-via-rainforest-portal-payments

Credits

christos-cantina-security