How severe is CVE-2023-38163?

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

Vulnerability in Microsoft Defender Security Intelligence Updates

CVE-2023-38163

Windows Defender Attack Surface Reduction Security Feature Bypass

Published 2023-09-12 · last modified 2026-06-17.

CVSS v3 metric

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

EPSS exploit prediction

EPSS: 0.007 (49.6th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.000

Affected products

Microsoft Defender Security Intelligence Updates — versions 1.0.0
Microsoft Windows Defender Security Intelligence Updates

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2023-38163 (vendor-advisory, Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2023-38163?: CVE-2023-38163 is a high-severity vulnerability in Microsoft Defender Security Intelligence Updates. CVSS score: 7.8/10. Published 2023-09-12.
How severe is CVE-2023-38163?: High severity. CVSS v3 base score is 7.8 out of 10.