CVE-2026-34983Published

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 …

Exact source revision recorded 27 Oct 2026 09:03:08 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

nvd · CVE-2026-34983

Published

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.

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Analyzed

Weakness classifications: CWE-416

Original publisher date fields

published: 2026-04-09T19:16:24.850

lastModified: 2026-10-26T21:10:00.170

1 source CPE criteria · context only

cpe:2.3:a:bytecodealliance:wasmtime:43.0.0:*:*:*:*:rust:*:*

The original JSON retains the logical configuration operators, exclusions and version bounds.

Source published: 9 Apr 2026 19:16:24 UTC
Source modified: 26 Oct 2026 21:10:00 UTC
Observed here: 27 Oct 2026 09:03:08 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 1.0 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS 3.1 · [email protected] · Primary · 5.0 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H