Wasmtime: Bit-packing in Cranelift compiler causes silent overflow and miscompilation
Wasmtime is a runtime for WebAssembly. Prior to 36.0.19 and 43.0.0, the Cranelift compiler backend bit-packs SSA value indices in a way that can silently overflow in release builds when compiling a sufficiently large or specially crafted Wasm function with many SSA values. The overflow can make Cranelift reference inco…
Severity critical: primary CNA CVSS 9.9 v3.1 (worst CNA-provided scenario) Not listed in this KEV snapshot. Forecast present in this snapshot.
Published 2026-10-23T21:23:27.669Z. Updated 2026-10-26T17:42:15.319Z.