Express Gateway through 1.16.11 OAuth 2.0 Refresh Token Validation Bypass

{
  "id": "4da12cd78b5dbd856c7c598dbc9662a38b131945aa8592d0f9d481a28fb3dbd5",
  "url": "https://osv.dev/vulnerability/CVE-2026-107162",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Express Gateway through 1.16.11 OAuth 2.0 Refresh Token Validation Bypass",
    "summary": "Express Gateway through 1.16.11 contains an authentication bypass vulnerability in the OAuth 2.0 refresh_token grant that fails to validate the token secret or issuing client. Attackers with any valid client credentials and the identifier portion of another user's refresh token can obtain that user's access token and impersonate them against oauth2-protected APIs.",
    "evidence": "osv:CVE-2026-107162",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-107162",
      "aliases": [
        "CVE-2026-107162"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/expressgateway/express-gateway",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "f7ff832c2294d49c3073ba59dc716907b3b5ad13"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.16.11"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.16.11"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.16.11",
            "v1.16.10",
            "v1.16.9",
            "v1.16",
            "v1.16.8",
            "v1.16.7",
            "v1.16.6",
            "v1.16.3",
            "v1.16.2",
            "v1.16.1",
            "v1.16.0",
            "v1.15.0",
            "v1.14.0",
            "v1.13.0",
            "v1.12.1",
            "v1.12.0",
            "v1.11.0",
            "v1.10.2",
            "v1.10.1",
            "v1.10.0",
            "v1.9.1",
            "v1.9.0",
            "v1.8.2",
            "v1.8.1",
            "v1.8.0",
            "v1.7.3",
            "v1.7.2",
            "v1.7.0",
            "v1.6.1",
            "v1.6.0",
            "v1.5.0",
            "v1.4.0",
            "v1.2.0",
            "v1.1.1",
            "v1.1.0",
            "v1.0.2",
            "v1.0.1",
            "v1.0.0",
            "v0.11.0",
            "v0.10.0",
            "v0.9.0",
            "v0.0.2",
            "0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-107162.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:33.806215010Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/107xxx/CVE-2026-107162.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-107162",
        "https://www.vulncheck.com/advisories/express-gateway-through-1.16.11-oauth-2.0-refresh-token-validation-bypass",
        "https://github.com/ExpressGateway/express-gateway/issues/1076",
        "https://github.com/ExpressGateway/express-gateway",
        "https://github.com/ExpressGateway/express-gateway/blob/45612814d12f65889ef3bdf80b2ed7ab9b557736/lib/policies/oauth2/oauth2-server.js#L221-L247",
        "https://github.com/ExpressGateway/express-gateway/blob/45612814d12f65889ef3bdf80b2ed7ab9b557736/lib/services/tokens/token.service.js#L100-L136"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-287"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/107xxx/CVE-2026-107162.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-107162",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 500947,
  "published_at": "2026-10-07T12:48:18.499+00:00"
}