Cloudanix VulnDB

CVE-2026-115889

Critical · 9.9

CVSS

9.9

EPSS

0.5%

Published

Oct 23, 2026

CISA due date

—

The record

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 incorrect IR values, causing arbitrary miscompilation, type confusion, and other attacker-controlled effects that may escape the Wasm sandbox on any architecture using the default Cranelift backend. This issue is fixed in versions 36.0.19 and 43.0.0.

Affected packages

Ecosystem Package Introduced Fixed

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