CVE-2026-34944
CVE-2026-34944 · Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 4.1 · Medium · EPSS 0.2% · Fix available
- Published
- Updated
Stack: system
Affected products and versions
wasmtime
- Versions
- < 24.0.7: Affected
- >= 25.0.0, < 36.0.7: Affected
- >= 37.0.0, < 42.0.2: Affected
- >= 43.0.0, < 44.0.1: Affected
No fix published
rust-wasmtime Debian:13
- Versions
- 26.0.1+dfsg-10
- 26.0.1+dfsg-3
- 26.0.1+dfsg-4
- 26.0.1+dfsg-5
- 26.0.1+dfsg-6
- 26.0.1+dfsg-7
- 26.0.1+dfsg-8
- 26.0.1+dfsg-9
- 27.0.0+dfsg-2
- 27.0.0+dfsg-3
- 27.0.0+dfsg-4
- 28.0.1+dfsg-1
- 28.0.1+dfsg-2
- 28.0.1+dfsg-3
- 29.0.1+dfsg-1
- 29.0.1+dfsg-2
- 29.0.1+dfsg-3
- 29.0.1+dfsg-4
- 29.0.1+dfsg-5
- 29.0.1+dfsg-6
- 29.0.1+dfsg-7
- 29.0.1+dfsg-8
- 36.0.11+dfsg-1
- 36.0.12+dfsg-1
- 36.0.12+dfsg-2
- 36.0.12+dfsg-3
- 36.0.13+dfsg-1
- 36.0.5+dfsg-1
- 36.0.5+dfsg-2
- 36.0.5+dfsg-3
- 36.0.5+dfsg-4
- 36.0.5+dfsg-5
- 36.0.6+dfsg-1
- 36.0.6+dfsg-2
- 36.0.6+dfsg-3
- 36.0.6+dfsg-4
- 36.0.6+dfsg-5
- 36.0.6+dfsg-6
- 36.0.6+dfsg-7
- 36.0.7+dfsg-1
- 36.0.8+dfsg-1
- 36.0.9+dfsg-1
- 36.0.9+dfsg-2
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
rust-wasmtime Debian:14
- Versions
- 26.0.1+dfsg-10
- 26.0.1+dfsg-3
- 26.0.1+dfsg-4
- 26.0.1+dfsg-5
- 26.0.1+dfsg-6
- 26.0.1+dfsg-7
- 26.0.1+dfsg-8
- 26.0.1+dfsg-9
- 27.0.0+dfsg-2
- 27.0.0+dfsg-3
- 27.0.0+dfsg-4
- 28.0.1+dfsg-1
- 28.0.1+dfsg-2
- 28.0.1+dfsg-3
- 29.0.1+dfsg-1
- 29.0.1+dfsg-2
- 29.0.1+dfsg-3
- 29.0.1+dfsg-4
- 29.0.1+dfsg-5
- 29.0.1+dfsg-6
- 29.0.1+dfsg-7
- 29.0.1+dfsg-8
- 36.0.5+dfsg-1
- 36.0.5+dfsg-2
- 36.0.5+dfsg-3
- 36.0.5+dfsg-4
- 36.0.5+dfsg-5
- 36.0.6+dfsg-1
- 36.0.6+dfsg-2
- 36.0.6+dfsg-3
- 36.0.6+dfsg-4
- 36.0.6+dfsg-5
- 36.0.6+dfsg-6
- 36.0.6+dfsg-7
- Affected ranges
- ECOSYSTEM: < 36.0.7+dfsg-1
Update to 36.0.7+dfsg-1
rust-wasmtime Ubuntu:24.04:LTS
- Versions
- 10.0.1+dfsg-7
- 15.0.1+dfsg-4
- 16.0.0+dfsg-2
- 16.0.0+dfsg-3
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
rust-wasmtime Ubuntu:25.10
- Versions
- 26.0.1+dfsg-3
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
rust-wasmtime Ubuntu:26.10
- Versions
- 36.0.5+dfsg-1
- 36.0.13+dfsg-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published
rust-wasmtime Ubuntu:26.04:LTS
- Versions
- 26.0.1+dfsg-3
- 26.0.1+dfsg-4
- 28.0.1+dfsg-3
- 29.0.1+dfsg-5
- 36.0.5+dfsg-1
- Affected ranges
- ECOSYSTEM: (−∞, +∞)
No fix published