Summaryinfo

A vulnerability described as critical has been identified in wasmi-labs wasmi up to 0.41.1/0.47.0/0.51.2/1.0.0. The affected element is an unknown function of the component WebAssembly Module Handler. Such manipulation leads to use after free. This vulnerability is traded as CVE-2025-66627. An attack has to be approached locally. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in wasmi-labs wasmi up to 0.41.1/0.47.0/0.51.2/1.0.0. It has been rated as critical. Affected by this issue is an unknown code block of the component WebAssembly Module Handler. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2025-66627 since 12/05/2025. The exploitation is known to be easy. Local access is required to approach this attack. The technical details are unknown and an exploit is not available.

Upgrading to version 0.41.2, 0.47.1, 0.51.3 or 1.0.1 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• wasmi-labs

Name

• wasmi

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10
• 0.11
• 0.12
• 0.13
• 0.14
• 0.15
• 0.16
• 0.17
• 0.18
• 0.19
• 0.20
• 0.21
• 0.22
• 0.23
• 0.24
• 0.25
• 0.26
• 0.27
• 0.28
• 0.29
• 0.30
• 0.31
• 0.32
• 0.33
• 0.34
• 0.35
• 0.36
• 0.37
• 0.38
• 0.39
• 0.40
• 0.41
• 0.41.0
• 0.41.1
• 0.42
• 0.43
• 0.44
• 0.45
• 0.46
• 0.47.0
• 0.51.0
• 0.51.1
• 0.51.2
• 1.0

Website

• Product: https://github.com/wasmi-labs/wasmi/

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