CVE-2026-34983
Publication date 9 April 2026
Last updated 10 July 2026
Ubuntu priority
Description
Wasmtime is a runtime for WebAssembly. In 43.0.0, cloning a wasmtime::Linker is unsound and can result in use-after-free bugs. This bug is not controllable by guest Wasm programs. It can only be triggered by a specific sequence of embedder API calls made by the host. Specifically, the following steps must occur to trigger the bug clone a wasmtime::Linker, drop the original linker instance, use the new, cloned linker instance, resulting in a use-after-free. This vulnerability is fixed in 43.0.1.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| rust-wasmtime | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy | Not in release |
Severity score breakdown
CVSS version:
Base score
1.0 · Low
Vector: CVSS:4.0/AV:P/AC:H/AT:P/PR:H/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
Base score
5.0 · Medium
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H