CVE-2026-115889
criticalWasmtime is a runtime for WebAssembly.
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/bytecodealliance/wasmtime/commit/ba8f7d70caa1825b7f64fa75cd9d03f4a438da... security-advisories@github.com
- https://github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56... security-advisories@github.com
- https://github.com/bytecodealliance/wasmtime/pull/12613 security-advisories@github.com
- https://github.com/bytecodealliance/wasmtime/pull/14818 security-advisories@github.com
- https://github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19 security-advisories@github.com
- https://github.com/bytecodealliance/wasmtime/releases/tag/v43.0.0 security-advisories@github.com
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-897f-g5gm-fmxm security-advisories@github.com