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?

Medium severity, with a CVSS score of 4, published 14 October 2026.

Which products and versions are affected?

Bytecode Alliance Wasmtime 49.0.0 to 49.0.2; wasmtime (crates.io) SEMVER:introduced=49.0.0,fixed=49.0.3.

Is there a fix for This vulnerability?

Yes. wasmtime (crates.io): upgrade to 49.0.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is This vulnerability attacked?

It is attacked over the network.

Check whether you run Bytecode Alliance Wasmtime 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.

Wasmtime overlapping string transcode panic in fused adapter

Severity: medium · CVSS 4 · Published 2026-10-14

Wasmtime is a WebAssembly runtime used to execute untrusted code. A flaw in string transcoding within a fused adapter can cause the runtime to panic and crash, disrupting any application relying on Wasmtime for code execution. An authenticated user with the ability to trigger specific operations could exploit this to cause a denial of service.

Technologies: Bytecode Alliance Wasmtime, wasmtime (crates.io). Vendors: Bytecode Alliance, 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?: Medium severity, with a CVSS score of 4, published 14 October 2026.
Which products and versions are affected?: Bytecode Alliance Wasmtime 49.0.0 to 49.0.2; wasmtime (crates.io) SEMVER:introduced=49.0.0,fixed=49.0.3.
Is there a fix for This vulnerability?: Yes. wasmtime (crates.io): upgrade to 49.0.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is This vulnerability attacked?: It is attacked over the network.
Am I affected?: Check whether you run Bytecode Alliance Wasmtime 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

wasmtime (crates.io): upgrade to 49.0.3 or later
```
cargo update -p wasmtime
```

Technical details

The vulnerability is a panic condition in the fused adapter when handling overlapping string transcoding operations. It requires an authenticated user (PR:L) and specific triggering conditions (AT:P) to reach the vulnerable code path. Exploitation results in high availability impact through denial of service via application crash.

Affected products

Bytecode Alliance Wasmtime 49.0.0 to 49.0.2

Identifiers

GHSA-54p9-vhhq-8f7q
RUSTSEC-2026-0360

Timeline

2026-10-14: disclosed
2026-10-14: patched

References

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