Nginx UI: Account Takeover via Missing `RequireSecureSession` on User Management Endpoint

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, the POST /api/users/:id user-management endpoint permits an authenticated user to change another user's password without passing RequireSecureSession, even though the self-service password-change path requires that step-up. An attacker with an authenticated account can change the initial administrator's password, invalidate existing administrator tokens, and then authenticate as the administrator. This issue is fixed in version 2.4.1.

Source published

12 Oct 2026 20:47:51 UTC

Source modified

13 Oct 2026 17:32:02 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, the POST /api/users/:id user-management endpoint permits an authenticated user to change another user's password without passing RequireSecureSession, even though the self-service password-change path requires that step-up. An attacker with an authenticated account can change the initial administrator's password, invalidate existing administrator tokens, and then authenticate as the administrator. This issue is fixed in version 2.4.1.

Source published

Oct 12, 2026, 8:47:51 PM (timezone not stated)

Source modified

Oct 13, 2026, 5:32:02 PM (timezone not stated)

Observed here

7 Nov 2026 15:21:48 UTC

Source terms

ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 4.0 · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Nginx UI is a web user interface for the Nginx web server. Prior to 2.4.1, the POST /api/users/:id user-management endpoint permits an authenticated user to change another user's password without passing RequireSecureSession, even though the self-service password-change path requires that step-up. An attacker with an authenticated account can change the initial administrator's password, invalidate existing administrator tokens, and then authenticate as the administrator. This issue is fixed in version 2.4.1.

Source published

12 Oct 2026 21:17:21 UTC

Source modified

13 Oct 2026 18:17:25 UTC

Observed here

25 Oct 2026 16:19:16 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

### Summary `POST /api/users/:id` allows any authenticated user to change any other user's password without `RequireSecureSession` (2FA verification). In contrast, the self password change endpoint `POST /api/user/password` correctly requires `RequireSecureSession`. This inconsistency enables any authenticated user to take over the initial admin account (user ID 1) by simply changing its password. ### Details nginx-ui enforces `RequireSecureSession` middleware on sensitive operations such as self password change (`api/user/router.go:55`), self profile update (`api/user/router.go:54`), settings modification (`api/settings/router.go:12`), and config file deletion/rename (`api/config/router.go:16-21`). However, the user management endpoint registered in `InitManageUserRouter` (`api/user/user.go:31-68`) is mounted on the `g` router group (`router/routers.go:92`) which only applies `middleware.AuthRequired()` and `middleware.Proxy()` — **no `RequireSecureSession()`**. As a result, `POST /api/users/:id` with a `password` field in the JSON body updates the target user's password with only basic JWT authentication. No 2FA or secure session verification is performed, even if the target user has 2FA enabled. The attack flow: 1. Attacker authenticates as any user (e.g., user ID 2). 2. Attacker sends `POST /api/users/1` with `{"password": "attacker-chosen"}`. 3. Admin (user ID 1) password is changed. All existing admin tokens are invalidated (`api/user/user.go:48-49`). 4. Attacker logs in as admin with the new password. 5. Admin is locked out. ### PoC [poc.zip](https://github.com/user-attachments/files/26971275/poc.zip) Please extract the uploaded compressed file before proceeding 1. docker compose up -d 2. python3 poc.py <img width="501" height="55" alt="스크린샷 2026-04-22 오후 10 26 29" src="https://github.com/user-attachments/assets/6562ede2-7c11-48da-b905-be9964f4f7b1" /> ### Impact - Any authenticated user can change any other user's password, including the initial admin (user ID 1). - Full account takeover of the admin account.

Source published

15 Oct 2026 20:11:45 UTC

Source modified

19 Oct 2026 21:41:14 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Publisher rating · HIGH

Nginx UI: Account Takeover via Missing `RequireSecureSession` on User Management Endpoint in github.com/0xJacky/Nginx-UI

Source published

19 Oct 2026 21:08:35 UTC

Source modified

19 Oct 2026 21:31:37 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.