ETK-2026-3415Zero's internal tracking ID, independent of the CVE number.

{
  "etk_id": "ETK-2026-3415",
  "cve_id": null,
  "display_id": "ETK-2026-3415",
  "ghsa_id": null,
  "euvd_id": null,
  "status": "retired",
  "anchor_state": "awaiting_cve",
  "title": "Unauthenticated token signing in Better Auth Expo plugin",
  "summary": "Servers that register the `expo()` plugin from affected `@better-auth/expo` releases can sign attacker-controlled authorization state using the application secret. An unauthenticated attacker who knows a user's email address may be able to take over that account and alter its email address; session-cache use can expand impact when a user ID is known. Wildcard `trustedOrigins` entries can also unintentionally trust malformed or unintended URLs.",
  "mitigation": "Upgrade both `@better-auth/expo` and `better-auth` to 1.7.16, or to 1.8.0-beta.5 on the beta release line, then rotate the application secret if the endpoint was reachable. Remove the `expo()` plugin if Expo social sign-in is not needed, and review wildcard entries in `trustedOrigins`.",
  "vendor": "npm",
  "product": "npm:@better-auth/expo",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.4.0-beta.6, < 1.7.16"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "1.7.16"
      ],
      "package_name": "@better-auth/expo",
      "purl": "pkg:npm/@better-auth/expo"
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.8.0-beta.0, < 1.8.0-beta.5"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "1.8.0-beta.5"
      ],
      "package_name": "@better-auth/expo",
      "purl": "pkg:npm/@better-auth/expo"
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        "< 1.7.16"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "1.7.16"
      ],
      "package_name": "better-auth",
      "purl": "pkg:npm/better-auth"
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.8.0-beta.0, < 1.8.0-beta.5"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "1.8.0-beta.5"
      ],
      "package_name": "better-auth",
      "purl": "pkg:npm/better-auth"
    }
  ],
  "cwes": [
    287
  ],
  "cvss_score": 9.1,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
  "epss_score": null,
  "epss_percentile": null,
  "epss_asof": null,
  "automation": "deterministic",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": null,
  "t0_at": null,
  "signals": {}
}