CVE-2026-40509: CSRF (CVSS 4.3)

Description

OpenEMR before 8.3.0 contains a cross-site request forgery vulnerability in the DICOM viewer. The web_path GET parameter in the DICOM viewer page is embedded unsanitized as a URL without validation against expected path formats. An attacker can craft a URL that causes an authenticated user with Patients - Documents permissions to make authenticated requests to arbitrary OpenEMR endpoints, enabling forced logout and other state-changing actions.

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CVSS v3.1 Score

4.3

MEDIUM

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

EPSS — Exploit Prediction

0.0013

Probability of exploitation

0.03%

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-352 Cross-Site Request Forgery

References

Other References

https://github.com/openemr/openemr/commit/f760adc7bddaf9d118e1a0d40590e686783ed21b https://github.com/openemr/openemr/releases/tag/v8_3_0 https://github.com/openemr/openemr/security/advisories/GHSA-wffp-pj5h-xqwp https://www.vulncheck.com/advisories/openemr-csrf-via-dicom-viewer-web-path-parameter

Frequently Asked Questions

What is CVE-2026-40509? +

OpenEMR before 8.3.0 contains a cross-site request forgery vulnerability in the DICOM viewer. The web_path GET parameter in the DICOM viewer page is embedded unsanitized as a URL without validation against expected path formats. An attacker can craft a URL that causes an authenticated user with Patients - Documents permissions to make authenticated requests to arbitrary OpenEMR endpoints, enabling forced logout and other state-changing actions. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2026-40509? +

CVE-2026-40509 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0013, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-40509? +

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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