Is CVE-2026-34983 actively exploited?

CVE-2026-34983 has no public evidence of in-the-wild exploitation as of 2026-04-15.

What is the CVSS score for CVE-2026-34983?

CVE-2026-34983 has a CVSS score of 1 (LOW severity). 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/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.

How do I patch CVE-2026-34983?

Patch guidance is available from bytecodealliance security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-34983.

Which products are affected by CVE-2026-34983?

1 product: bytecodealliance wasmtime.

CVE-2026-34983 - remediation guidance & executive summary

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.

CVSS Metrics

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/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
Attack Vector: physical
Complexity: high
Privileges: high
User Action: active
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-416 · Use After Free

Metadata

Primary Vendor: BYTECODEALLIANCE
Published: 4/9/2026
Last Modified: 4/15/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

bytecodealliance : wasmtime

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-34983. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-34983

View on NIST NVD

CVE-2026-34983 vulnerability