High · published December 9, 2025
🚨 A cunning use after free vulnerability hides in Wasmi versions 0.41.0 through 1.0.0, where a mischievous WebAssembly module can lead to memory corruption! ⚡ Think of Wasmi like a busy restaurant kitchen where a chef is trying to serve multiple orders but accidentally forgets to dispose of an old dish — this can lead to confusion and mix-ups in what’s served to customers. In this case, memory areas that shouldn’t be reused are being accessed again, leading to chaos! An attacker could exploit this vulnerability to manipulate memory, potentially leading to unauthorized information disclosure or even arbitrary code execution. This is a serious risk, as it opens the door for attackers to run malicious code in your system, creating an absolutely devastating scenario where your application can be controlled remotely!
Think of Wasmi like a busy restaurant kitchen where a chef is trying to serve multiple orders but accidentally forgets to dispose of an old dish — this can lead to confusion and mix-ups in what’s served to customers. In this case, memory areas that shouldn’t be reused are being accessed again, leading to chaos! This use after free vulnerability occurs within the linear memory implementation of Wasmi, where memory that should have been freed can still be accessed. This can lead to corrupted data or execution of unintended code when certain memory growth conditions are met.
An attacker could exploit this vulnerability to manipulate memory, potentially leading to unauthorized information disclosure or even arbitrary code execution. This is a serious risk, as it opens the door for attackers to run malicious code in your system, creating an absolutely devastating scenario where your application can be controlled remotely! To protect your systems, upgrade to the fixed versions: 0.41.2, 0.47.1, 0.51.3, or 1.0.1. Additionally, consider limiting the maximum linear memory sizes where feasible to mitigate potential exploitation. Don’t wait — act now! You've got this! With these steps, you'll be securing your systems and keeping your code tight! 🛡️
| Product | Versions | Fixed in |
|---|---|---|
| wasmi-labs/wasmi | ≥ 0.41.0, < 0.41.2 | 0.41.2 |
| wasmi-labs/wasmi | ≥ 0.47.0, < 0.47.1 | 0.47.1 |
| wasmi-labs/wasmi | ≥ 0.51.0, < 0.51.3 | 0.51.3 |
| wasmi-labs/wasmi | all versions | — |