openemr vulnerability

OpenEMR through 8.2.0 contains a stored cross-site scripting vulnerability in the patient portal template system that allows authenticated administrators to inject arbitrary HTML and JavaScript by storing malicious payloads through the template save mode, which only filters literal PHP open tags. Attackers can exploit the lack of output encoding at the template retrieval endpoint combined with missing HttpOnly cookie attributes to exfiltrate session tokens via document.cookie access, enabling full session hijacking of any admin, clinician, or portal patient who views a poisoned template.

Published 3 Aug 2026Updated 9 Sep 20262 sources
CVSS 4.8

What happened

OpenEMR through 8.2.0 contains a stored cross-site scripting vulnerability in the patient portal template system that allows authenticated administrators to inject arbitrary HTML and JavaScript by storing malicious payloads through the template save mode, which only filters literal PHP open tags. Attackers can exploit the lack of output encoding at the template retrieval endpoint combined with missing HttpOnly cookie attributes to exfiltrate session tokens via document.cookie access, enabling full session hijacking of any admin, clinician, or portal patient who views a poisoned template.

Affected versions

openemr: 0 through 8.2.0 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.