Auth bypass in Ni Systemlink

CVE-2026-4129

There is an improper access control vulnerability in NI SystemLink that may allow an authenticated user with limited privileges to access host operating system files and directories that should be restricted. This vulnerability affects NI SystemLink and NI SystemLink Server versions prior to 2026 Q3.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.3th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-4129: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4129?
CVE-2026-4129 is a high-severity vulnerability in Ni Systemlink, classified under Missing Authorization. CVSS score: 8.1/10. Published 2026-09-10.
How severe is CVE-2026-4129?
High severity. CVSS v3 base score is 8.1 out of 10.