CVE-2026-115893 — Vulnerability intelligence
bytecodealliance — wasmtime, wasmtime, wasmtime
Published:
- CVSS
- 9.9
- CISA KEV
- Not listed; not proof of no exploitation
Original source text (not a translation)
Wasmtime: Cranelift backend on aarch64 can jump to incorrect target on large Wasm `br_table` instruction
## Summary
When running with the Cranelift compiler backend on an aarch64 target, Wasmtime can compile a Wasm module with more than ~256k targets on one `br_table` instruction in a way that results in an incorrect conditional branch target. This conditional branch could then jump to arbitrary other code (at an user-controlled offset), leading to arbitrary sandbox escapes.
## Impact
Any Wasmtime engine running on aarch64 with default settings can be forced to jump to arbitrary code by a user-controlled Wasm module. All versions of Wasmtime/Cranelift that support aarch64, since the initial release of that support in 2020 (before Wasmtime v1.0), are affected.
## Patches
Wasmtime v36.0.19, v48.0.7, and v49.0.4 have been released which all fix this issue.