CVE-2026-34944 (GCVE-0-2026-34944)

Vulnerability from cvelistv5 – Published: 2026-04-09 18:38 – Updated: 2026-04-13 15:38
VLAI
Title
Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64
Summary
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.
Severity
4.1 (Medium)
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
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-13 15:06 UTC
CWE
Assigner
References
Impacted products
Vendor Product Version CPE status
bytecodealliance wasmtime Affected: < 24.0.7
Affected: >= 25.0.0, < 36.0.7
Affected: >= 37.0.0, < 42.0.2
Affected: >= 43.0.0, < 44.0.1
guessed Create a notification for this product.
Show details on NVD website
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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