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.

Project Subscriptions

No data.

Advisories
Source ID Title
Github GHSA Github GHSA GHSA-qqfj-4vcm-26hv Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 09 Apr 2026 19:00:00 +0000

Type Values Removed Values Added
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.
Title Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64
Weaknesses CWE-248
References
Metrics cvssV4_0

{'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'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-09T18:38:16.182Z

Reserved: 2026-03-31T17:27:08.660Z

Link: CVE-2026-34944

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-04-09T19:16:24.187

Modified: 2026-04-09T19:16:24.187

Link: CVE-2026-34944

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses