CVE-2026-34944
Fixed in a distro release EPSS <1%CVSS 4.1
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.
Products: bytecodealliance wasmtime
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| crates.io | wasmtime | 24.0.7 |
| crates.io | wasmtime | 36.0.7 |
| crates.io | wasmtime | 42.0.2 |
| crates.io | wasmtime | 43.0.1 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | wash | no fix |
| Chainguard | wasmcloud | 2.0.4-r0 |
| Chainguard | wizer | 11.0.3-r10 |
| Chainguard | yara-x | 1.15.0-r2 |
| Chainguard | zed | 0.228.0-r3 |
| Debian 13 | rust-wasmtime | no fix |
| Debian 14 | rust-wasmtime | 36.0.7+dfsg-1 |
| Ubuntu 24.04 LTS | rust-wasmtime | no fix |
| Ubuntu 25.10 | rust-wasmtime | no fix |
| Ubuntu 26.04 LTS | rust-wasmtime | no fix |
| Ubuntu 26.10 | rust-wasmtime | no fix |
| Wolfi | wash | no fix |
| Wolfi | wasmcloud | 2.0.4-r0 |
| Wolfi | wizer | 11.0.3-r10 |
| Wolfi | yara-x | 1.15.0-r2 |
| Wolfi | zed | 0.228.0-r3 |