---
id: RUSTSEC-2026-0380
aliases:
  - GHSA-897f-g5gm-fmxm
title: Bit-packing in Cranelift compiler causes silent overflow and miscompilation
summary: Bit-packing in Cranelift compiler causes silent overflow and miscompilation
severity: critical
cvss: 9.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'
vendor: wasmtime
product: wasmtime
ecosystem: rust
affected:
  - 'wasmtime >= 37.0.0, < 43.0.0'
patched:
  - wasmtime 43.0.0
published: '2026-10-19'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T11:15:37.073985819Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/RUSTSEC-2026-0380'
references:
  - url: 'https://crates.io/crates/wasmtime'
  - url: 'https://rustsec.org/advisories/RUSTSEC-2026-0380.html'
  - url: 'https://github.com/bytecodealliance/wasmtime/pull/12613'
tags:
  - osv
  - rust
ingestedAt: '2026-10-21T11:54:42.770Z'
---

## Overview

This is an entry in the RustSec database for the Wasmtime security advisory
located at
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-897f-g5gm-fmxm
For more information see the GitHub-hosted security advisory.

## Affected packages

- `wasmtime >= 37.0.0, < 43.0.0`

## Remediation

Upgrade to a patched release:

- `wasmtime 43.0.0`