CVE-2026-33303
CWE-79Published: March 19, 2026· Updated: Mar 20, 2026
Official Description
OpenEMR is a free and open source electronic health records and medical practice management application. Versions prior to 8.0.0.2 are vulnerable to stored cross-site scripting (XSS) via unescaped `portal_login_username` in the portal credential print view. A patient portal user can set their login username to an XSS payload, which then executes in a clinic staff member's browser when they open the "Create Portal Login" page for that patient. This crosses from the patient session context into the staff/admin session context. Version 8.0.0.2 fixes the issue.
Technical Analysis
CVE-2026-33303 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (2)
Quick Facts
Related CVEs (CWE-79)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-33303 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts