{
  "id": "CVE-2026-115889",
  "url": "https://spydr.io/cve/CVE-2026-115889",
  "published": "2026-10-23T22:16:58.400Z",
  "modified": "2026-10-23T22:16:58.550Z",
  "score": 9.9,
  "severity": "critical",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
  "score_source": "github.com",
  "epss": null,
  "epss_percentile": null,
  "exploited": false,
  "kev": null,
  "ssvc_exploitation": null,
  "vendors": [
    "bytecodealliance"
  ],
  "products": [
    "bytecodealliance wasmtime"
  ],
  "cwes": [
    "CWE-197",
    "CWE-843"
  ],
  "description": "Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with many SSA values. The overflow can make Cranelift reference incorrect IR values, causing arbitrary miscompilation, type confusion, and other attacker-controlled effects that may escape the Wasm sandbox on any architecture using the default Cranelift backend. This issue is fixed in versions 36.0.19 and 43.0.0.",
  "status": "Deferred",
  "score_type": "Secondary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 9.9,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "https://github.com/bytecodealliance/wasmtime/commit/ba8f7d70caa1825b7f64fa75cd9d03f4a438dae0",
      "tags": []
    },
    {
      "url": "https://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa",
      "tags": []
    },
    {
      "url": "https://github.com/bytecodealliance/wasmtime/pull/12613",
      "tags": []
    },
    {
      "url": "https://github.com/bytecodealliance/wasmtime/pull/14818",
      "tags": []
    },
    {
      "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19",
      "tags": []
    },
    {
      "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v43.0.0",
      "tags": []
    },
    {
      "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-897f-g5gm-fmxm",
      "tags": []
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115889",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}