CVE-2026-44216CWE-770

Wasmtime: Panic when allocating a table exceeding the size of the host's address space

Medium · published May 14, 2026

CVSS v4.0
5.9
EPSS
1%
Percentile
47.0
In the wild
Unconfirmed
What it is

Wasmtime is a runtime for WebAssembly. From 30.0.0 to 36.0.8, 43.0.2, and 44.0.1, Wasmtime's allocation logic for a WebAssembly table contained checked arithmetic which panicked on overflow. This overflow is possible to trigger, and thus panic, when a table with an extremely large size is allocated. This is possible with the WebAssembly memory64 proposal where tables can have sizes in the 64-bit range as opposed to the previous 32-bit range which would not overflow. The panic happens when attempting to create a very large table, such as when instantiating a WebAssembly module or component. This vulnerability is fixed in 36.0.8, 43.0.2, and 44.0.1.

The record
Technical detail
CVSS v4.0
5.9 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS
0.00581 · 47.0th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-05-14T14:54Z
EPSS history
Timeline
  • 14 MAY 14:54Z
    Wasmtime: Panic when allocating a table exceeding the size of the host's address space
    cvelistv5