Auth bypass in 0xjacky Nginx-Ui

CVE-2026-33031

Nginx UI is a web user interface for the Nginx web server. Prior to version 2.3.4, a user who was disabled by an administrator can use previously issued API tokens for up to the token lifetime. In practice, disabling a compromised account does not actually terminate that user’s access, so an attacker who already stole a JWT can continue reading and modifying protected resources after the account is marked disabled. Since tokens can be used to create new accounts, it is possible the disabled user to maintain the privilege. Version 2.3.4 patches the issue.

Published · last modified .

CVSS v3 metric

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

EPSS exploit prediction

EPSS: 0.004 (31.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-33031: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33031?
CVE-2026-33031 is a high-severity vulnerability in 0xjacky Nginx-Ui, classified under Improper Access Control. CVSS score: 8.1/10. Published 2026-04-20.
How severe is CVE-2026-33031?
High severity. CVSS v3 base score is 8.1 out of 10.