CVE-2026-34944
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 4.0
- 4.1
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 5.7
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H - EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 13% of CVEs (scores of 2026-10-26)
- CWE
- CWE-248
- Published
- Modified
- Record from
- the NVD, synced
Affected
- bytecodealliance:wasmtime
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-qqfj-4vcm-26hv | crates.io | wasmtime | <24.0.7 | 24.0.7 |
| GHSA-qqfj-4vcm-26hv | crates.io | wasmtime | >=25.0.0 <36.0.7 | 36.0.7 |
| GHSA-qqfj-4vcm-26hv | crates.io | wasmtime | >=37.0.0 <42.0.2 | 42.0.2 |
| GHSA-qqfj-4vcm-26hv | crates.io | wasmtime | >=43.0.0 <43.0.1 | 43.0.1 |
| RUSTSEC-2026-0087 | crates.io | wasmtime | >=0.0.0-0 <24.0.7 >=25.0.0 <36.0.7 >=37.0.0 <42.0.2 >=43.0.0 <43.0.1 | 24.0.7, 36.0.7, 42.0.2, 43.0.1 |