Improper Check for Unusual or Exceptional Conditions Affecting wasmtime package, versions >=39.0.0 <40.0.4>=41.0.0 <41.0.4
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RUST-WASMTIME-15347366
- published25 Feb 2026
- disclosed24 Feb 2026
- creditUnknown
Introduced: 24 Feb 2026
NewCVE-2026-27195 (opens in a new tab)How to fix?
Upgrade wasmtime to version 40.0.4, 41.0.4 or higher.
Overview
Affected versions of this package are vulnerable to Improper Check for Unusual or Exceptional Conditions in the call_async function. An attacker can cause the application to panic and terminate unexpectedly by dropping the future returned by wasmtime::component::[Typed]Func::call_async before it resolves, and then invoking another call_async call on the same component instance.
Note: This is only exploitable if the component-model-async feature is enabled at compile time and the host embedder drops unresolved call_async futures.
Workaround
This vulnerability can be mitigated by:
Disabling the
component-model-asyncCargo featureEnsuring every
call_asyncfuture is awaited until completionRefraining from using the
Storeagain after dropping a not-yet-resolvedcall_asyncfuture.