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OpenAdvisories
High · 8.4 CVE-2025-66627 EUVD-2025-201826GHSA-g4v2-cjqp-rfmq

Wasmi's Linear Memory has a Critical Use After Free Vulnerability

Published Dec 9, 2025 · Updated Dec 9, 2025 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
wasmi-labs wasmi >= 0.41.0, < 0.41.2, >= 0.42.0, < 0.47.1, >= 0.50.0, < 0.51.3, >= 1.0.0, < 1.0.1 —

Affected packages

EcosystemPackageAffectedFixedRecord
crates.io wasmi >= 0.41.0, < 0.41.2 0.41.2 GHSA-g4v2-cjqp-rfmq
crates.io wasmi >= 0.42.0, < 0.47.1 0.47.1 GHSA-g4v2-cjqp-rfmq
crates.io wasmi >= 0.50.0, < 0.51.3 0.51.3 GHSA-g4v2-cjqp-rfmq
crates.io wasmi >= 1.0.0, < 1.0.1 1.0.1 GHSA-g4v2-cjqp-rfmq

References