CVE-2026-115893
Deferred
Deferred - Pending Action
Incorrect Branch Target in Wasmtime Cranelift aarch64 Sandbox Escape
Vulnerability report for CVE-2026-115893, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-23
Last updated on: 2026-10-23
Assigner: GitHub, Inc.
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| bytecodealliance | wasmtime | < 36.0.19 |
| bytecodealliance | wasmtime | >= 37.0.0, < 48.0.7 |
| bytecodealliance | wasmtime | >= 49.0.0, < 49.0.4 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-691 | The code does not sufficiently manage its control flow during execution, creating conditions in which the control flow can be modified in unexpected ways. |
