How severe is CVE-2021-42312?

High severity. CVSS v3 base score is 7.8 out of 10.

Vulnerability in Microsoft Defender For Iot

CVE-2021-42312

Microsoft Defender for IoT Elevation of Privilege Vulnerability

Published 2021-12-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (43.4th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 43.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Microsoft Defender For Iot
Microsoft Defender For Iot — versions 22.0.0

References

portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-42312 (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-42312?: CVE-2021-42312 is a high-severity vulnerability in Microsoft Defender For Iot. CVSS score: 7.8/10. Published 2021-12-15.
How severe is CVE-2021-42312?: High severity. CVSS v3 base score is 7.8 out of 10.