{
  "cveId": "CVE-2026-115889",
  "url": "https://patchblox.com/security/cve/CVE-2026-115889",
  "summary": "CVE-2026-115889 is fixed in rust-wasmtime on 1 platform by DEBIAN-CVE-2026-115889 (version 36.0.20\u002Bdfsg-1), released November 3, 2026. It is not reported as exploited. Patch Radar priority: Urgent.",
  "title": "Wasmtime: Bit-packing in Cranelift compiler causes silent overflow and miscompilation",
  "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.",
  "published": "2026-10-23T22:16:58Z",
  "severity": "Critical",
  "cvss": 9.9,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
  "cwe": "Numeric Truncation Error",
  "epss": 0.00454,
  "epssPercentile": 0.39663,
  "priority": "Urgent",
  "priorityTier": 2,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-115889",
  "fixes": [
    {
      "platform": "linux",
      "product": "rust-wasmtime",
      "release": "Debian 14",
      "fixedVersion": "36.0.20\u002Bdfsg-1",
      "fix": "DEBIAN-CVE-2026-115889",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-115889",
      "released": "2026-11-03T18:58:21Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-10T01:44:33Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}