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.
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-qqfj-4vcm-26hv
Published: 2026-04-09
Updated: 2026-04-09
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P
Severity: Medium
Base Score: 6.2
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: Medium
Base Score: 4.1
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
Severity: Medium
EPSS: 0.00006