ETK-2026-3390Zero's internal tracking ID, independent of the CVE number.

{
  "etk_id": "ETK-2026-3390",
  "cve_id": null,
  "display_id": "ETK-2026-3390",
  "ghsa_id": "GHSA-3xjw-gv43-3w62",
  "euvd_id": null,
  "status": "published",
  "anchor_state": "awaiting_cve",
  "title": "Login account-switching authentication bypass in Mastodon",
  "summary": "Mastodon login handling can allow a local user to obtain access to a different inactive local account without its password. Exploitation requires a valid local account, a target account that has been inactive for at least three months and lacks two-factor authentication, and successful guessing of the target's email sign-in token.",
  "mitigation": "Upgrade Mastodon to 4.7.5 or 5.0.0-alpha.4 or later, as appropriate for the deployed release line. Restrict access to local accounts and ensure users enable two-factor authentication while upgrades are applied.",
  "vendor": null,
  "product": "Mastodon",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 4.8.0-alpha.3, < 5.0.0-alpha.3"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "5.0.0-alpha.4"
      ],
      "package_name": "Mastodon",
      "purl": null
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        "4.7.4"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "4.7.5"
      ],
      "package_name": "Mastodon",
      "purl": null
    }
  ],
  "cwes": [
    287
  ],
  "cvss_score": 7,
  "cvss_src": "ethiack_provisional",
  "cvss_vector": null,
  "epss_score": null,
  "epss_percentile": null,
  "epss_asof": null,
  "automation": "contextual",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 16.716931666666667,
  "t0_at": null,
  "signals": {
    "trigger_signal": {
      "at": "2026-11-03T16:48:28+00:00",
      "days": -0.10269740973379629,
      "is_lower_bound": true,
      "measured_at": "2026-11-03T19:16:21.115453+00:00",
      "url": "https://github.com/mastodon/mastodon/security/advisories/GHSA-3xjw-gv43-3w62"
    }
  }
}