CVE-2026-115893
bytecodealliance wasmtime
Published 23 Oct 2026 · updated 23 Oct 2026 · Deferred
9.9 Critical · CVSS 3.1, github.com
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.
References
- github.com/bytecodealliance/wasmtime/commit/222ff3a65dab9aa7011f8c246937751a0bac5abd
- github.com/bytecodealliance/wasmtime/commit/994549891c8a706cb4f2809f9d17b9f67b31e618
- github.com/bytecodealliance/wasmtime/commit/e61df1b454be9313d61a5f8de07722a421139bbe
- github.com/bytecodealliance/wasmtime/commit/f517bd6e890c7c1291ab9fe05d8cc0c9f11e56aa
- 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
- github.com/bytecodealliance/wasmtime/releases/tag/v49.0.4
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-mghf-wjfp-p5xm