CVE-2022-39393: Bytecodealliance Wasmtime

High severity, CVSS 8.6. EPSS: 0.7% chance of exploitation in the next 30 days.

Wasmtime is a standalone runtime for WebAssembly. Prior to versions 2.0.2 and 1.0.2, there is a bug in Wasmtime's implementation of its pooling instance allocator where when a linear memory is reused for another instance the initial heap snapshot of the prior instance can be visible, erroneously to the next instance. This bug has been patched and users should upgrade to Wasmtime 2.0.2 and 1.0.2. Other mitigations include disabling the pooling allocator and disabling the `memory-init-cow`.

Affected products

• Bytecodealliance Wasmtime: before 1.0.2 (fixed in 1.0.2); from 2.0.0, before 2.0.2 (fixed in 2.0.2)

Published 2022-11-10. Last modified 2026-06-17.