Integer overflow in Wasmtime - #VU129536
Published: May 4, 2026
Vulnerability identifier: #VU129536
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-190
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Bytecode Alliance
Affected software:
Wasmtime
Wasmtime
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to checked arithmetic that panics on overflow in WebAssembly table allocation logic when instantiating a WebAssembly module or component with an extremely large table. A remote user can supply a crafted WebAssembly module or component that allocates an extremely large table to cause a denial of service.
The issue affects the on-demand instance allocator and requires the memory64 WebAssembly feature to be enabled.
Remediation
Install security update from vendor's website.