CVE-2025-66627 HIGH

CVE-2025-66627: Wasmi's Linear Memory has a Critical Use After Free Vulnerability

Vendor Wasmi-Labs
Product wasmi
Weakness CWE-416
Published December 9, 2025
Last update December 9, 2025

CVSS base score

8.4/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Wasmi is a WebAssembly interpreter focused on constrained and embedded systems. In versions 0.41.0, 0.41.1, 0.42.0 through 0.47.1, 0.50.0 through 0.51.2 and 1.0.0, Wasmi's linear memory implementation leads to a Use After Free vulnerability, triggered by a WebAssembly module under certain memory growth conditions. This issue potentially leads to memory corruption, information disclosure, or code execution. This issue is fixed in versions 0.41.2, 0.47.1, 0.51.3 and 1.0.1. To workaround this issue, consider limiting the maximum linear memory sizes where feasible.

Key dates

02Disclosure timeline

December 9, 2025 CVE published
December 9, 2025 Record updated