Nezha through 2.2.3 Host Header Injection via OAuth2 redirect_uri

{
  "id": "0749cacc8c3c4e37e2192f5d1387536f6455ca391de355e9a7e996ae22045331",
  "url": "https://osv.dev/vulnerability/CVE-2026-101090",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Nezha through 2.2.3 Host Header Injection via OAuth2 redirect_uri",
    "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 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.",
    "evidence": "osv:CVE-2026-101090",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-101090",
      "aliases": [
        "CVE-2026-101090",
        "GHSA-rf68-8gjr-36q7",
        "GO-2026-6486"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/nezhahq/nezha",
              "type": "GIT",
              "events": [
                {
                  "introduced": "3d74cd9431a48fa89c6489689eac82a872799ea0"
                },
                {
                  "last_affected": "3d74cd9431a48fa89c6489689eac82a872799ea0"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "2.2.3"
                      },
                      {
                        "last_affected": "2.2.3"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.2.3",
            "v2.2.3"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-101090.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.319081485Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101090.json",
        "https://github.com/nezhahq/nezha/security/advisories/GHSA-rf68-8gjr-36q7",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-101090",
        "https://www.vulncheck.com/advisories/nezha-through-2.2.3-host-header-injection-via-oauth2-redirect-uri"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-601"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101090.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-101090",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 499501,
  "published_at": "2026-09-27T20:50:00.857+00:00"
}