# RUSTSEC-2026-0379 - Cranelift backend on aarch64 can jump to incorrect target on large Wasm `br_table` instruction

Source: https://junglewise.ai/threats/rustsec-2026-0379-cranelift-backend-on-aarch64-can-jump-to-incorrect-f8a31e7c  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-19  
License: CC BY 4.0 with a link back

Severity: low · CVSS 3.1 · Published 2026-10-19

Cranelift backend on aarch64 can jump to incorrect target on large Wasm `br_table` instruction

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

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Low severity, with a CVSS score of 3.1, published 19 October 2026.

**Which products and versions are affected?** wasmtime (crates.io) SEMVER:introduced=0.0.0-0,fixed=36.0.19,introduced=37.0.0,fixed=48.0.7,introduced=49.0.0,fixed=49.0.4.

**Is there a fix for This vulnerability?** Yes. wasmtime (crates.io): upgrade to 49.0.4 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected?** Check whether you run 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

- wasmtime (crates.io): upgrade to 49.0.4 or later

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


## Affected products

- wasmtime (crates.io) SEMVER:introduced=0.0.0-0,fixed=36.0.19,introduced=37.0.0,fixed=48.0.7,introduced=49.0.0,fixed=49.0.4

## Identifiers

- GHSA-mghf-wjfp-p5xm
- RUSTSEC-2026-0379

## 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)