What is CVE-2021-42563?

CVE-2021-42563 is a high-severity vulnerability in Microsoft Windows, classified under Unquoted Search Path or Element. CVSS score: 7.8/10. Published 2021-11-12.

How severe is CVE-2021-42563?

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

Vulnerability in Microsoft Windows

CVE-2021-42563

There is an Unquoted Service Path in NI Service Locator (nisvcloc.exe) in versions prior to 18.0 on Windows. This may allow an authorized local user to insert arbitrary code into the unquoted service path and escalate privileges.

Published 2021-11-12 · last modified 2026-06-17.

CVSS v3 metric

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

EPSS exploit prediction

EPSS: 0.002 (12.8th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

Weakness classification (CWE)

CWE-428 — Unquoted Search Path or Element

References

www.ni.com/en-us/support/documentation/supplemental/21/unquoted-service-path-in… (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-42563?: CVE-2021-42563 is a high-severity vulnerability in Microsoft Windows, classified under Unquoted Search Path or Element. CVSS score: 7.8/10. Published 2021-11-12.
How severe is CVE-2021-42563?: High severity. CVSS v3 base score is 7.8 out of 10.