CVE-2026-46518
HIGHOpenEMR is a free and open source electronic health records and medical practice management application. Prior to version 8.0.0.1, a stored cross-site scripting vulnerability in the…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
OpenEMR is a free and open source electronic health records and medical practice management application. Prior to version 8.0.0.1, a stored cross-site scripting vulnerability in the prescription CSS/HTML multi-print feature allows a patient portal user to execute arbitrary JavaScript in a clinician's browser session. Patient demographic fields (name, address) are rendered without output encoding in multiprintcss_header(), and portal patients can write attacker-controlled HTML directly into patient_data by calling the PUT api/patient/:num endpoint, which bypasses the intended audit review workflow. Because the XSS fires in the clinician's authenticated session on the main OpenEMR interface, the attacker can access CSRF tokens, session data, and perform actions as the clinician — crossing the patient-to-clinician trust boundary. This issue has been patched in version 8.0.0.1.
Affected Products
openemropen-emrDetection & mitigation playbook
Vendor / applianceDetect
Inventory every open-emr openemr deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the open-emr openemr security patch or hotfix for CVE-2026-46518 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-46518 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-46518. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-46518 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-46518 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.