Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64_CVE-2026-34944

{
    "lastseen": "",
    "description": "Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, On x86-64 platforms with SSE3 disabled Wasmtime's compilation of the f64x2.splat WebAssembly instruction with Cranelift may load 8 more bytes than is necessary. When signals-based-traps are disabled this can result in a uncaught segfault due to loading from unmapped guard pages. With guard pages disabled it's possible for out-of-sandbox data to be loaded, but this data is not visible to WebAssembly guests. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.",
    "published": "2026-04-09T18:38:16.182Z",
    "modified": "2026-04-09T18:38:16.182Z",
    "type": "cve",
    "title": "Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64",
    "source": "GitHub_M",
    "references": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-qqfj-4vcm-26hv",
    "id": "CVE-2026-34944",
    "bulletinFamily": "",
    "cwe": [
        "CWE-248"
    ],
    "cvelist": null,
    "sourceData": "bytecodealliance wasmtime < 24.0.7\nbytecodealliance wasmtime >= 25.0.0, < 36.0.7\nbytecodealliance wasmtime >= 37.0.0, < 42.0.2\nbytecodealliance wasmtime >= 43.0.0, < 44.0.1",
    "sourceHref": "",
    "cvss": {
        "score": 4.1,
        "severity": "MEDIUM",
        "vector": "CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "wasmtime",
    "version": "< 24.0.7",
    "vendor": "bytecodealliance",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}