CVE-2025-66627: wasmi Use-After-Free — Fix

Description

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.

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CVSS v3.1 Score

8.4

HIGH

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

Weakness Type (CWE)

CWE-416 Use After Free

Affected Products

Vendor	Product	Versions
wasmi-labs	wasmi	0.41.0 — 0.41.2
wasmi-labs	wasmi	0.47.0 — 0.47.1
wasmi-labs	wasmi	0.51.0 — 0.51.3
wasmi-labs	wasmi	All

References

Advisories & Patches

https://github.com/wasmi-labs/wasmi/security/advisories/GHSA-g4v2-cjqp-rfmq

Frequently Asked Questions

What is CVE-2025-66627? +

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. It has a CVSS v3.1 base score of 8.4 (HIGH).

How severe is CVE-2025-66627? +

CVE-2025-66627 has a CVSS v3.1 score of 8.4 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-66627? +

CVE-2025-66627 affects products from wasmi-labs, specifically: wasmi. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-66627? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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