CVE-2026-33031

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.

Details

The application exposes an account-level disable control through the users management API. Login process correctly enforces that control:
https://github.com/0xJacky/nginx-ui/blob/6ec542fd97abf2c5950f374f78a32938ad0030e6/internal/user/login.go#L29-L31

However, token-based authentication does not enforce the same check (This code validates token structure and expiry, but returns that user object without checking user.Status.):
https://github.com/0xJacky/nginx-ui/blob/6ec542fd97abf2c5950f374f78a32938ad0030e6/internal/user/user.go#L44-L139

There’s also no token revocation feature, unlike when a password is changed:
https://github.com/0xJacky/nginx-ui/blob/6ec542fd97abf2c5950f374f78a32938ad0030e6/api/user/user.go#L38-L51

As a result, a disabled user can continue to have full API access. In particular, since that includes account creation, they can create a new account and keep operating even after the JWT expires.

PoC

The issue was validated with version 2.3.3 using the uozi/nginx-ui:sha-c92ec0a docker image.

View the PoC video:

https://github.com/user-attachments/assets/7a5175cb-2f79-4c1b-adad-e7d0bf2ea2bd

Administrators who rely on "disable user" as an authentication or authorization control can be bypassed.

The disabled user can keep reading sensitive configuration and executing authenticated state-changing actions allowed to that account.

The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.

CVE-2026-33031 has a CVSS score of 8.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.9.10-0.20260314152518-7b66578adb47); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-33031? CVE-2026-33031 is a high-severity incorrect authorization vulnerability in github.com/0xJacky/Nginx-UI (go), affecting versions < 1.9.10-0.20260314152518-7b66578adb47. It is fixed in 1.9.10-0.20260314152518-7b66578adb47. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
2. How severe is CVE-2026-33031? CVE-2026-33031 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/0xJacky/Nginx-UI are affected by CVE-2026-33031? github.com/0xJacky/Nginx-UI (go) versions < 1.9.10-0.20260314152518-7b66578adb47 is affected.
4. Is there a fix for CVE-2026-33031? Yes. CVE-2026-33031 is fixed in 1.9.10-0.20260314152518-7b66578adb47. Upgrade to this version or later.
5. Is CVE-2026-33031 exploitable, and should I be worried? Whether CVE-2026-33031 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-33031 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-33031? Upgrade github.com/0xJacky/Nginx-UI to 1.9.10-0.20260314152518-7b66578adb47 or later.