XSS in Openemr
CVE-2026-40508
OpenEMR before 8.3.0 contains a stored cross-site scripting vulnerability in the patient portal template import handler that allows authenticated attackers with Forms Administration permissions to upload template files containing arbitrary HTML or JavaScript. Attackers can inject malicious scripts through the template upload functionality, which are stored without sanitization and execute in the browser of any other Forms Administration user who views the template in the HTML editor.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (20.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-5293-8q47-cf44) (vendor-advisory)
- OpenEMR v8_3_0 Release Notes (release-notes)
- Patch Commit (patch)
- www.vulncheck.com/advisories/openemr-stored-xss-via-patient-portal-template-imp… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-40508?
- CVE-2026-40508 is a medium-severity vulnerability in Openemr, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-08-19.
- How severe is CVE-2026-40508?
- Medium severity. CVSS v3 base score is 5.4 out of 10.