What is CVE-2018-16521?

CVE-2018-16521 is a critical-severity vulnerability in Openmrs HTML Form Entry, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 9.8/10. Published 2018-09-05.

How severe is CVE-2018-16521?

Critical severity. CVSS v3 base score is 9.8 out of 10.

XXE in Openmrs HTML Form Entry

CVE-2018-16521

An XML External Entity (XXE) vulnerability exists in HTML Form Entry 3.7.0, as distributed in OpenMRS Reference Application 2.8.0.

Vulnerability class: XXE (XML External Entity)

Published 2018-09-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.019 (79.0th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 79th percentile — 79.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.019 · newest: 0.019 · change: 0.000

Affected products

Openmrs HTML Form Entry — versions 3.7.0
Openmrs Reference Application — versions 2.8.0

Weakness classification (CWE)

CWE-611 — Improper Restriction of XML External Entity Reference (XXE)

References

github.com/openmrs/openmrs-module-htmlformentry/pull/138 (Patch, Third Party Advisory)
github.com/openmrs/openmrs-module-htmlformentry/pull/137 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2018-16521?: CVE-2018-16521 is a critical-severity vulnerability in Openmrs HTML Form Entry, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 9.8/10. Published 2018-09-05.
How severe is CVE-2018-16521?: Critical severity. CVSS v3 base score is 9.8 out of 10.