CVE-2026-115893 PUBLISHED

Wasmtime: Cranelift backend on aarch64 can jump to incorrect target on large Wasm `br_table` instruction

Assigner: GitHub_M
Reserved: 23.10.2026 Published: 23.10.2026 Updated: 23.10.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS Score: 9.9

Product Status

Vendor bytecodealliance
Product wasmtime
Versions
  • Version < 36.0.19 is affected
  • Version >= 37.0.0, < 48.0.7 is affected
  • Version >= 49.0.0, < 49.0.4 is affected

References

Problem Types

  • CWE-691: Insufficient Control Flow Management CWE