{"id":"CVE-2026-34944","summary":"Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64","details":"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.","aliases":["GHSA-qqfj-4vcm-26hv","RUSTSEC-2026-0087"],"modified":"2026-04-22T05:14:13.951509981Z","published":"2026-04-09T18:38:16.182Z","related":["CGA-9gqp-p96h-8rj6"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-248"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34944.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"43.0.0"},{"fixed":"44.0.1"}]}]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34944.json"},{"type":"ADVISORY","url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-qqfj-4vcm-26hv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34944"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/bytecodealliance/wasmtime","events":[{"introduced":"0"},{"fixed":"a15daff0bfc965d1656ddcf9beaa1d085c3a7410"},{"introduced":"0b195ef5db76c02fb5392ec1418c58bdc5537d41"},{"fixed":"09539085b9b514b65d5c51e2905dc38f6eb414b9"},{"introduced":"7b3d6ae79e9153a2477668062f5622c10333925f"},{"fixed":"403f9929d4e13ed87c76471d4f4bc8d381c876eb"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0"},{"fixed":"24.0.7"},{"introduced":"25.0.0"},{"fixed":"36.0.7"},{"introduced":"37.0.0"},{"fixed":"42.0.2"}]}}],"versions":["cranelift-v0.60.0","cranelift-v0.61.0","cranelift-v0.69.0","dev","v0.12.0","v0.16.0","v0.17.0","v0.18.0","v0.19.0","v0.20.0","v0.21.0","v0.22.0","v0.23.0","v0.24.0","v0.25.0","v0.26.0","v0.27.0","v0.28.0","v0.29.0","v0.30.0","v0.31.0","v0.32.0","v0.33.0","v0.34.0","v0.35.0","v24.0.0","v24.0.1","v24.0.2","v24.0.3","v24.0.4","v24.0.5","v24.0.6","v36.0.0","v36.0.1","v36.0.2","v36.0.3","v36.0.4","v36.0.5","v36.0.6","v42.0.0","v42.0.1"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-34944.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}