Is CVE-2026-34944 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-34944 being exploited in the wild.

How severe is CVE-2026-34944?

Medium severity, with a CVSS score of 5.7, published 9 April 2026.

Which products and versions are affected?

wasmtime (crates.io) SEMVER:introduced=0,fixed=24.0.7, SEMVER:introduced=0.0.0-0,fixed=24.0.7,introduced=25.0.0,fixed=36.0.7,introduced=37.0.0,fixed=42.0.2,introduced=43.0.0,fixed=43.0.1.

Is there a fix for CVE-2026-34944?

Yes. wasmtime (crates.io): upgrade to 24.0.7, 43.0.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Am I affected by CVE-2026-34944?

Check whether you run Bytecodealliance 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.

CVE-2026-34944: Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64

CVE-2026-34944 · Severity: medium · CVSS 5.7 · Published 2026-04-09

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, On x86-64 platforms with SSE3 disabled Wasmtime's compilation of the f64x2.splat WebAssembly instruction with Cranelift may load 8 more bytes than is necessary. When signals-based-traps are disabled this can result in a uncaught segfault due to loading from unmapped guard pages. With guard pages disabled it's possible for out-of-sandbox data to be loaded, but this data is not visible to WebAssembly guests. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.

Technologies: Bytecodealliance Wasmtime, wasmtime (crates.io). Vendors: Bytecodealliance, crates.io.

Quick answers

Is CVE-2026-34944 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-34944 being exploited in the wild.
How severe is CVE-2026-34944?: Medium severity, with a CVSS score of 5.7, published 9 April 2026.
Which products and versions are affected?: wasmtime (crates.io) SEMVER:introduced=0,fixed=24.0.7, SEMVER:introduced=0.0.0-0,fixed=24.0.7,introduced=25.0.0,fixed=36.0.7,introduced=37.0.0,fixed=42.0.2,introduced=43.0.0,fixed=43.0.1.
Is there a fix for CVE-2026-34944?: Yes. wasmtime (crates.io): upgrade to 24.0.7, 43.0.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2026-34944?: Check whether you run Bytecodealliance 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 24.0.7, 43.0.1 or later
```
cargo update -p wasmtime
```

Affected products

Bytecodealliance Wasmtime
wasmtime (crates.io) SEMVER:introduced=0,fixed=24.0.7, SEMVER:introduced=0.0.0-0,fixed=24.0.7,introduced=25.0.0,fixed=36.0.7,introduced=37.0.0,fixed=42.0.2,introduced=43.0.0,fixed=43.0.1

Identifiers

CVE-2026-34944
GHSA-qqfj-4vcm-26hv
RUSTSEC-2026-0087

References

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