CVE-2026-34944

Description

A flaw was found in Wasmtime, a runtime for WebAssembly. On x86-64 platforms with SSE3 disabled, Wasmtime's Cranelift compiler backend may load additional data beyond the intended memory boundary when compiling the 'f64x2.splat' WebAssembly instruction. This out-of-bounds read can lead to a Denial of Service (DoS) through an uncaught segmentation fault if signals-based traps are disabled. While it could also load out-of-sandbox data if guard pages are disabled, this information is not accessible to WebAssembly guests.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score4.75.7N/A
Attack VectorLocalNetworkN/A
Attack ComplexityHighLowN/A
Privileges RequiredNoneLowN/A
User InteractionRequiredRequiredN/A
ScopeUnchangedUnchangedN/A
ConfidentialityNoneNoneN/A
Integrity ImpactNoneNoneN/A
Availability ImpactHighHighN/A

Vector

Red Hat: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

NVD: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H

Understanding the Weakness (CWE)

CWE-466

Confidentiality,Integrity

Technical Impact: Read Memory; Modify Memory

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