CVE-2026-42222: Nginx UI is a web user interface for the Nginx web server

This week

HIGH 8.1REMOTEWATCHLISTDOWNGRADE

CVE-2026-42222 is a high-severity flaw (CVSS 8.1) affecting nginx ui. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Nginx UI is a web user interface for the Nginx web server. In version 2.3.5, an unauthenticated bootstrap takeover exists in nginx-ui during the initial installation window exposed by POST /api/install. At time of publication no public patches are available.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action
On your watchlist

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 73%)
CISA exploited list	No
Weakness	CWE-284, CWE-306
Published	2026-05-04
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: nginxui

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-04 21:16 UTCPublished CVE record published
2026-10-26 19:10 UTCUpdated Record last modified

nginxui nginx ui DOWNGRADE

Affected: 2.3.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.3.5

1. Check installed version

apt-cache policy nginx-ui || rpm -q nginx-ui || nginx-ui --version

2. No fixed release: DOWNGRADE to a release before 2.3.5 (Debian / Ubuntu)

apt-cache madison nginx-ui sudo apt install nginx-ui=<VERSION_BEFORE_2.3.5> sudo apt-mark hold nginx-ui

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list nginx-ui sudo dnf downgrade nginx-ui-<VERSION_BEFORE_2.3.5> sudo dnf versionlock add nginx-ui

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-42222?

nginx ui: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-42222 being exploited?

CVE-2026-42222 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-42222 affect?

CVE-2026-42222 affects nginx ui. Severity is high (CVSS 8.1). Nginx UI is a web user interface for the Nginx web server. In version 2.3.5, an unauthenticated bootstrap takeover exists in nginx-ui during the initial installation window exposed by POST /api/install. At time of publication no public patc

How urgent is CVE-2026-42222?

Priority 50/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action; On your watchlist

Software pages

nginx vulnerabilities · Bootstrap vulnerabilities

Related CVEs

CVE-2026-34403 HIGH 8.1 UPGRADE Nginx UI is a web user interface for the Nginx web server
CVE-2026-42221 HIGH 8.1 UPGRADE Nginx UI is a web user interface for the Nginx web server
CVE-2026-42220 MEDIUM 6.5 UPGRADE Nginx UI is a web user interface for the Nginx web server
CVE-2026-42223 MEDIUM 6.5 UPGRADE Nginx UI is a web user interface for the Nginx web server
CVE-2026-44015 HIGH 8.5 UPGRADE Nginx UI is a web user interface for the Nginx web server

References

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