#VU125758 Out-of-bounds read in Wasmtime - CVE-2026-34944
Published: April 10, 2026
Vulnerability identifier: #VU125758
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-34944
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerable software:
Wasmtime
Wasmtime
Software vendor:
Bytecode Alliance
Bytecode Alliance
Description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in Cranelift's compilation of the f64x2.splat WebAssembly instruction on x86-64 when processing a memory-loaded value without SSE3. A local user can execute crafted WebAssembly that triggers the widened load to cause a denial of service.
Exploitation requires guard pages to be enabled and signals-based-traps to be disabled. User interaction is required.
Remediation
Install security update from vendor's website.