---
id: CVE-2026-101090
title: >-
  Nezha 2.2.3 contains a Host header injection regression in the OAuth2 redirect
  endpoint
summary: >-
  Nezha 2.2.3 contains a Host header injection regression in the OAuth2 redirect
  endpoint. When the new optional dashboard_host setting is empty,
  /api/v1/oauth2/{provider} (cmd/dashboard/controller/oauth2.go) reflects the
  attacker-supplied…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-601
vendor: nezhahq
product: nezha
affected:
  - nezha >= 2.2.3 <= 2.2.3
published: '2026-09-27'
updated: '2026-09-27'
sourceUpdated: '2026-09-27T21:17:03.003'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101090'
references:
  - url: 'https://github.com/nezhahq/nezha/security/advisories/GHSA-rf68-8gjr-36q7'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/nezha-through-2.2.3-host-header-injection-via-oauth2-redirect-uri
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-27T20:58:01.538Z'
---

## Overview

Nezha 2.2.3 contains a Host header injection regression in the OAuth2 redirect endpoint. When the new optional dashboard_host setting is empty, /api/v1/oauth2/{provider} (cmd/dashboard/controller/oauth2.go) reflects the attacker-supplied HTTP Host header into the redirect_uri sent to the identity provider instead of falling back to the configured install_host. An attacker who induces a victim to begin OAuth2 login via a request that reaches Nezha with a forged Host header can cause an attacker-controlled callback URL to be used as the redirect_uri; if the OAuth2 provider accepts it, the victim's authorization code is delivered to the attacker origin, allowing the attacker to complete the OAuth2 login/binding flow and take over the account. This regresses the fix for GHSA-9rc6-8cjv-rcvx and is configuration-dependent (dashboard_host empty). At the time of the advisory no patched version was available.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.