CVE-2026-40508: XSS (CVSS 5.4)

Description

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.

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CVSS v3.1 Score

5.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0021

Probability of exploitation

0.11%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://github.com/openemr/openemr/commit/ba316dd1d8de1291102da3f20f64240729ff899e https://github.com/openemr/openemr/releases/tag/v8_3_0 https://github.com/openemr/openemr/security/advisories/GHSA-5293-8q47-cf44 https://www.vulncheck.com/advisories/openemr-stored-xss-via-patient-portal-template-import-handler https://github.com/openemr/openemr/security/advisories/GHSA-5293-8q47-cf44

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2026-40508? +

CVE-2026-40508 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0021, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-40508? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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