CVE-2026-19445

{
  "etk_id": "ETK-2026-129",
  "cve_id": "CVE-2026-19445",
  "display_id": "CVE-2026-19445",
  "ghsa_id": "GHSA-7jvw-f348-84gq",
  "euvd_id": "EUVD-2026-90077",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Use-after-free in CPython server-side SSL context handling",
  "summary": "CPython TLS servers may mishandle an SSL context's lifetime when an SNI callback switches the context and the original context is not retained. An unauthenticated TLS client can then cause a server crash or reach a call through released memory. This requires the affected SNI callback configuration; TLS clients and servers using a context attached to the listening socket are not affected.",
  "mitigation": "Upgrade CPython to 3.16.0. Until upgrading, retain references to every SSL context that installs an SNI callback for the entire server lifetime.",
  "vendor": "Python Software Foundation",
  "product": "CPython",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 0, < 3.16.0"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "3.16.0"
      ],
      "package_name": "CPython",
      "purl": null
    }
  ],
  "cwes": [
    416
  ],
  "cvss_score": 9.2,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N",
  "epss_score": 0.0043,
  "epss_percentile": 0.3586,
  "epss_asof": "2026-10-20",
  "automation": "contextual",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 37.0654268,
  "t0_at": "2026-09-30T16:16:04.923000+00:00",
  "signals": {
    "public_poc": {
      "at": "2026-10-02T01:46:32+00:00",
      "days": 1.396146724537037,
      "is_lower_bound": false,
      "measured_at": "2026-09-30T16:16:04.923000+00:00",
      "url": "https://github.com/abraxas/cve-2026-19445-sni-uaf"
    },
    "trigger_signal": {
      "at": "2026-09-30T16:16:04.923000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-09-30T16:16:04.923000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-19445"
    }
  }
}