RCE in 0xjacky Nginx-Ui

CVE-2026-42238

Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.8, nginx-ui exposes a backup restore endpoint (POST /api/restore) that is completely unauthenticated during the first 10 minutes after process startup on any fresh installation. An unauthenticated remote attacker can upload a crafted backup archive that overwrites the application's configuration file (app.ini) and SQLite database. Because the attacker controls the restored app.ini, they can inject an arbitrary OS command into the TestConfigCmd setting. After the application automatically restarts to apply the restored config, a single follow-up request triggers that command as the user running nginx-ui — typically root in Docker deployments. This issue has been patched in version 2.3.8.

Vulnerability class: RCE (Remote Code Execution)

EPSS: 0.008 (53.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-42238?
CVE-2026-42238 is a critical-severity vulnerability in 0xjacky Nginx-Ui, classified under Code Injection. CVSS score: 9.8/10. Published 2026-05-04.
How severe is CVE-2026-42238?
Critical severity. CVSS v3 base score is 9.8 out of 10.