# CVE-2023-27477: RUSTSEC-2023-0093 - Miscompilation of `i8x16.select` with the same inputs on x86\_64

Source: https://junglewise.ai/threats/cve-2023-27477-wasmtime-vulnerable-to-miscompilation-of-i8x16-select-with-the  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-03-03  
License: CC BY 4.0 with a link back

CVE-2023-27477 · Severity: low · CVSS 3.1 · Published 2023-03-03

Miscompilation of `i8x16.select` with the same inputs on x86\_64

Technologies: [cranelift-codegen (crates.io)](https://junglewise.ai/threats/technologies/cranelift-codegen), [wasmtime (crates.io)](https://junglewise.ai/threats/technologies/wasmtime). Vendors: [crates.io](https://junglewise.ai/threats/vendors/crates-io).

## Quick answers

**Is CVE-2023-27477 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2023-27477 being exploited in the wild.

**How severe is CVE-2023-27477?** Low severity, with a CVSS score of 3.1, published 3 March 2023.

**Which products and versions are affected?** cranelift-codegen (crates.io) SEMVER:introduced=0.88.0,fixed=0.91.1; wasmtime (crates.io) SEMVER:introduced=0.0.0-0,fixed=4.0.1,introduced=5.0.0,fixed=5.0.1,introduced=6.0.0,fixed=6.0.1, SEMVER:introduced=1.0.0,fixed=4.0.1.

**Is there a fix for CVE-2023-27477?** Yes. cranelift-codegen (crates.io): upgrade to 0.91.1 or later; wasmtime (crates.io): upgrade to 4.0.1, 6.0.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2023-27477?** Check whether you run cranelift-codegen (crates.io) or wasmtime (crates.io) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- cranelift-codegen (crates.io): upgrade to 0.91.1 or later

  ```sh
  cargo update -p cranelift-codegen
  ```

- wasmtime (crates.io): upgrade to 4.0.1, 6.0.1 or later

  ```sh
  cargo update -p wasmtime
  ```


## Affected products

- cranelift-codegen (crates.io) SEMVER:introduced=0.88.0,fixed=0.91.1
- wasmtime (crates.io) SEMVER:introduced=0.0.0-0,fixed=4.0.1,introduced=5.0.0,fixed=5.0.1,introduced=6.0.0,fixed=6.0.1, SEMVER:introduced=1.0.0,fixed=4.0.1

## Identifiers

- CVE-2023-27477
- GHSA-xm67-587q-r2vw
- RUSTSEC-2023-0093

## Related threats

- [RUSTSEC-2026-0422 - Typed functions with `i31` or `nullref` arguments may panic due to insufficient type-check](https://junglewise.ai/threats/rustsec-2026-0422-typed-functions-with-i31-or-nullref-arguments-may-0545dc2b)
- [Wasmtime type confusion with host-created struct types](https://junglewise.ai/threats/rustsec-2026-0423-cross-engine-type-confusion-with-host-created-struct-89fe3f0e)
- [Wasmtime unchecked memory usage in borrowed resource transfer](https://junglewise.ai/threats/rustsec-2026-0424-unchecked-memory-usage-in-transferring-borrowed-b297503c)
- [Wasmtime Cranelift aarch64 br_table sandbox escape](https://junglewise.ai/threats/cve-2026-115893-wasmtime-is-a-runtime-for-webassembly-prior-to-36-0-19-48-0-7)
- [Wasmtime component-model type-check bypass in stream/future lowering](https://junglewise.ai/threats/cve-2026-115892-wasmtime-is-a-runtime-for-webassembly-from-46-0-0-until-48-0-7)