CVE-2026-42238: GO-2026-5129 - Nginx-UI is Vulnerable to Unauthenticated Remote Code Execution via Backup Restore in github.com/0xJacky/nginx-ui

CVE-2026-42238 · Severity: critical · CVSS 9.8 · Published 2026-05-04

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.

Technologies: github.com/0xJacky/Nginx-UI (Go), Nginxui Nginx Ui. Vendors: Go, Nginxui.

Quick answers

Is CVE-2026-42238 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-42238 being exploited in the wild.
How severe is CVE-2026-42238?
Critical severity, with a CVSS score of 9.8, published 4 May 2026.
Which products and versions are affected?
github.com/0xJacky/Nginx-UI (Go) SEMVER:introduced=0, SEMVER:introduced=0,fixed=2.3.8.
Is there a fix for CVE-2026-42238?
Yes. github.com/0xJacky/Nginx-UI (Go): upgrade to 2.3.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-42238?
Check whether you run github.com/0xJacky/Nginx-UI (Go) or Nginxui Nginx Ui at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • github.com/0xJacky/Nginx-UI (Go): upgrade to 2.3.8 or later
    go get github.com/0xJacky/Nginx-UI@v2.3.8

Affected products

  • github.com/0xJacky/Nginx-UI (Go) SEMVER:introduced=0, SEMVER:introduced=0,fixed=2.3.8
  • Nginxui Nginx Ui

Identifiers

  • CVE-2026-42238
  • GHSA-4pvg-prr3-9cxr
  • GO-2026-5129

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