Reflected Cross-Site Scripting Vulnerability in OpenEMR Patient Portal by OpenEMR
CVE-2026-40507

5.1MEDIUM

Key Information:

Vendor

Openemr

Status
Openemr
Vendor
CVE Published:
19 August 2026

What is CVE-2026-40507?

OpenEMR versions prior to 8.3.0 contain a vulnerability in the patient portal template import handler, where the templateHtml GET parameter is reflected in responses without proper sanitization. This flaw permits threat actors to construct a malicious URL that, when accessed by an authenticated user with Forms Administration permissions, can execute arbitrary JavaScript within their browser. This security gap opens up potential session hijacking opportunities, compromising user accounts and data integrity.

Affected Version(s)

openemr 0

References

https://github.com/openemr/openemr/security/advisories/GH...
vendor-advisory
https://github.com/openemr/openemr/releases/tag/v8_3_0
release-notes
https://github.com/openemr/openemr/commit/ba316dd1d8de129...
patch

CVSS V4

Score:
5.1
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Alex Williams from Pellera Technologies
VulnCheck
.