CVE-2026-115893

CRITICAL 9.9

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

CVSS Score

9.9

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-691
Vendor	bytecodealliance
Product	wasmtime
Published	Oct 23, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

bytecodealliance / wasmtime

< 36.0.19 >= 37.0.0, < 48.0.7 >= 49.0.0, < 49.0.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗