Description
Wasmtime is a runtime for WebAssembly. Prior to 36.0.19, 48.0.7, and 49.0.4, the Cranelift compiler backend on aarch64 can compile a Wasm br_table instruction with more than approximately 256,000 targets so that it has an incorrect conditional branch target. The branch can then jump to arbitrary other code at a user-controlled offset, allowing a user-controlled Wasm module to escape the sandbox on aarch64 engines using the default Cranelift backend. This issue is fixed in versions 36.0.19, 48.0.7, and 49.0.4.
References10
- github.com/bytecodealliance/wasmtime/commit/222ff3a65dab9aa7011…
- github.com/bytecodealliance/wasmtime/commit/994549891c8a706cb4f…
- github.com/bytecodealliance/wasmtime/commit/e61df1b454be9313d61…
- github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291a…
- github.com/bytecodealliance/wasmtime/pull/14818
- github.com/bytecodealliance/wasmtime/pull/14819
- github.com/bytecodealliance/wasmtime/pull/14820
- github.com/bytecodealliance/wasmtime/pull/14826
- github.com/bytecodealliance/wasmtime/releases/tag/v36.0.19
- github.com/bytecodealliance/wasmtime/releases/tag/v48.0.7
Metrics
- CVSS 3.1
-
9.9
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 63 · as of 8 November 2026
- CWE
- CWE-691
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