CVE-2026-34983

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Source
https://cve.org/CVERecord?id=CVE-2026-34983
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-34983.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-34983
Aliases
Downstream
Related
Published
2026-04-09T18:47:26.575Z
Modified
2026-04-22T05:14:15.280352042Z
Severity
  • 1.0 (Low) CVSS_V4 - 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 CVSS Calculator
Summary
Wasmtime has a use-after-free bug after cloning `wasmtime::Linker`
Details

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.

Database specific 
{
    "cwe_ids": [
        "CWE-416"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34983.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/bytecodealliance/wasmtime

Affected ranges

Type
GIT
Repo
https://github.com/bytecodealliance/wasmtime
Events
Introduced
be23469ece57c0be64904f12111c8d808b0ce4ac
Fixed
cd4b6ed9b2a59cd3f317bff812126dd6a0e92dd2
Database specific 
{
    "source": "AFFECTED_FIELD",
    "extracted_events": [
        {
            "introduced": "43.0.0"
        },
        {
            "fixed": "43.0.1"
        }
    ]
}

Affected versions

v43.*
v43.0.0

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-34983.json"