Not a U.S. government website. NDD is an independent vulnerability database by Volerion and is not affiliated with or endorsed by NIST or NVD.

CVE-2026-34983 Details

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.

Metrics

CVSS 3.x Severity and Vector Strings:

NIST: [email protected]CVSS-B:5 MEDIUMVector:CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URL	Source(s)	Tag(s)
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hfr4-7c6c-48w2	CISA-ADP	MitigationVendor Advisory
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hfr4-7c6c-48w2	[email protected]	MitigationVendor Advisory

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-416	Use After Free	[email protected]

Affected Products

Product	Versions
bytecodealliance wasmtime	43.0.0
CPE cpe:2.3:a:bytecodealliance:wasmtime:43.0.0:::::rust:: Remediation No remediation found in references.

Change History

5 change records found show changes

Date	Action	Recorded By
Jun 17, 2026	CVE Modified	[email protected]
Jun 17, 2026	CVE Modified	CISA-ADP
Apr 15, 2026	Initial Analysis	[email protected]
Apr 13, 2026	CVE Modified	CISA-ADP
Apr 9, 2026	New CVE Received	[email protected]