FKIE_CVE-2026-115889

Vulnerability from fkie_nvd - Published: 2026-10-23 22:16 - Updated: 2026-10-23 22:16
Severity
9.9 (Critical) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Summary
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.
References
security-advisories@github.comhttps://github.com/bytecodealliance/wasmtime/commit/ba8f7d70caa1825b7f64fa75cd9d03f4a438dae0
security-advisories@github.comhttps://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa
security-advisories@github.comhttps://github.com/bytecodealliance/wasmtime/pull/12613
security-advisories@github.comhttps://github.com/bytecodealliance/wasmtime/pull/14818
security-advisories@github.comhttps://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19
security-advisories@github.comhttps://github.com/bytecodealliance/wasmtime/releases/tag/v43.0.0
security-advisories@github.comhttps://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-897f-g5gm-fmxm
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "wasmtime",
          "vendor": "bytecodealliance",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 36.0.19"
            },
            {
              "status": "affected",
              "version": "\u003e= 37.0.0, \u003c 43.0.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-115889",
  "lastModified": "2026-10-23T22:16:58.550",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.9,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.1,
        "impactScore": 6.0,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-23T22:16:58.400",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/bytecodealliance/wasmtime/commit/ba8f7d70caa1825b7f64fa75cd9d03f4a438dae0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/bytecodealliance/wasmtime/pull/12613"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/bytecodealliance/wasmtime/pull/14818"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v43.0.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-897f-g5gm-fmxm"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-197"
        },
        {
          "lang": "en",
          "value": "CWE-843"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}



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