What is CVE-2021-43990?

CVE-2021-43990 is a medium-severity vulnerability in Fanuc Roboguide, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 6.1/10. Published 2022-04-20.

How severe is CVE-2021-43990?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XXE in Fanuc Roboguide

CVE-2021-43990

The affected product is vulnerable to a network-based attack by threat actors supplying a crafted, malicious XML payload designed to trigger an external entity reference call.

Vulnerability class: XXE (XML External Entity)

Published 2022-04-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.007 (51.0th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: +0.000

Affected products

Fanuc Roboguide — versions All

Weakness classification (CWE)

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

References

www.cisa.gov/uscert/ics/advisories/icsa-22-109-03 (US Government Resource, Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-43990?: CVE-2021-43990 is a medium-severity vulnerability in Fanuc Roboguide, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 6.1/10. Published 2022-04-20.
How severe is CVE-2021-43990?: Medium severity. CVSS v3 base score is 6.1 out of 10.