CVE-2022-31146

What it is

Wasmtime is a standalone runtime for WebAssembly. There is a bug in the Wasmtime's code generator, Cranelift, where functions using reference types may be incorrectly missing metadata required for runtime garbage collection. This means that if a GC happens at runtime then the GC pass will mistakenly think these functions do not have live references to GC'd values, reclaiming them and deallocating them. The function will then subsequently continue to use the values assuming they had not been GC'd, leading later to a use-after-free. This bug was introduced in the migration to the `regalloc2` register allocator that occurred in the Wasmtime 0.37.0 release on 2022-05-20. This bug has been patched and users should upgrade to Wasmtime version 0.38.2. Mitigations for this issue can be achieved by disabling the reference types proposal by passing `false` to `wasmtime::Config::wasm_reference_types` or downgrading to Wasmtime 0.36.0 or prior.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure.

Exploit odds

1.2% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2022-07-21 04:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:44 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.2% in the next 30 days (EPSS).
• Severity: 6.4 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2022-07-21 04:15 UTC

Last modified

2026-06-17 04:44 UTC

Exploit probability

1.2% · EPSS, next 30 days

Weakness

CWE-416 · Use after free

Record status

Modified

Affected

• Bytecodealliance cranelift-codegen < 0.85.2
• Bytecodealliance Wasmtime < 0.38.2

Attack profile CVSS 3.1 · 6.4

Attack vector

Network

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

Low

Availability

Low

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-2022-31146.md and follow it. Check whether this project is affected by CVE-2022-31146. 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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