What is CVE-2026-42222?

CVE-2026-42222 is a high-severity vulnerability in 0xjacky Nginx-Ui, classified under Improper Access Control. CVSS score: 8.1/10. Published 2026-05-04.

How severe is CVE-2026-42222?

High severity. CVSS v3 base score is 8.1 out of 10.

Auth bypass in 0xjacky Nginx-Ui

CVE-2026-42222

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.

Published 2026-05-04 · last modified 2026-06-17.

CVSS v3 metric

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

EPSS exploit prediction

EPSS: 0.005 (39.6th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.001

Affected products

0xjacky Nginx-Ui — versions = 2.3.5
Nginxui nginx Ui — versions 2.3.5

Weakness classification (CWE)

References

github.com/0xJacky/nginx-ui/security/advisories/GHSA-mxqh-q9h6-v8pq (Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-42222?: CVE-2026-42222 is a high-severity vulnerability in 0xjacky Nginx-Ui, classified under Improper Access Control. CVSS score: 8.1/10. Published 2026-05-04.
How severe is CVE-2026-42222?: High severity. CVSS v3 base score is 8.1 out of 10.