CVE-2022-39393

What it is

Wasmtime is a standalone runtime for WebAssembly. Prior to versions 2.0.2 and 1.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator where when a linear memory is reused for another instance the initial heap snapshot of the prior instance can be visible, erroneously to the next instance. This bug has been patched and users should upgrade to Wasmtime 2.0.2 and 1.0.2. Other mitigations include disabling the pooling allocator and disabling the `memory-init-cow`.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

Exploit odds

0.9% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2022-11-10 20:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:58 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.9% in the next 30 days (EPSS).
• Severity: 8.6 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2022-11-10 20:15 UTC

Last modified

2026-06-17 04:58 UTC

Exploit probability

0.9% · EPSS, next 30 days

Weakness

CWE-226

Record status

Modified

Affected

• Bytecodealliance Wasmtime < 1.0.2
• Bytecodealliance Wasmtime < 2.0.2

Attack profile CVSS 3.1 · 8.6

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2022-39393.md and follow it. Check whether this project is affected by CVE-2022-39393. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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