{"affected":[{"defaultStatus":"unaffected","product":"openemr","source":"CNA: VulnCheck","vendor":"openemr","versions":[{"lessThan":"8.4.0","status":"affected","version":"0","versionType":"semver"},{"status":"unaffected","version":"8.4.0","versionType":"semver"}]}],"cveId":"CVE-2026-124481","cwes":["CWE-639"],"description":"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.","epss":{"date":"2026-11-10","percentile":0.15724,"score":0.00244},"exploits":[{"kind":"exploit","source":"ADP: CISA-ADP","url":"https://github.com/openemr/openemr/security/advisories/GHSA-525m-fch5-vqqm"}],"kev":null,"metrics":[{"score":7.1,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"},{"score":6.5,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","version":"3.1"},{"score":7.1,"severity":"high","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/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","version":"4.0"},{"score":6.5,"severity":"medium","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}],"modifiedAt":1794491655618,"publishedAt":1794143760737,"references":[{"source":"CNA: VulnCheck","tags":["vendor-advisory"],"url":"https://github.com/openemr/openemr/security/advisories/GHSA-525m-fch5-vqqm"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/openemr-before-8.4.0-cross-patient-payment-tampering-via-rainforest-portal-payments"},{"source":"ADP: CISA-ADP","tags":["exploit"],"url":"https://github.com/openemr/openemr/security/advisories/GHSA-525m-fch5-vqqm"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/openemr/openemr/security/advisories/GHSA-525m-fch5-vqqm"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://www.vulncheck.com/advisories/openemr-before-8.4.0-cross-patient-payment-tampering-via-rainforest-portal-payments"}],"remediation":[],"revision":"e964515947bd7e2fd670a809a7b350ee2bfa7dc482fe4a6e5825a46abde3cd3d","sources":[{"modifiedAt":1794491655618,"name":"CNA: VulnCheck","retrievedAt":1794492562997,"url":"https://www.cve.org/CVERecord?id=CVE-2026-124481"},{"modifiedAt":1794347185193,"name":"NVD","retrievedAt":1794356376944,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-124481"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794377605901,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-124481"}],"ssvc":{"assessedAt":1794491624721,"automatable":"no","exploitation":"poc","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"OpenEMR before 8.4.0 Cross-Patient Payment Tampering via Rainforest Portal Payments","updatedAt":1794492562997}