{"id":"CVE-2026-34983","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-34983","generatedAt":"2026-10-28T09:26:53.677Z","title":"In 43.0.0, cloning a wasmtime::Linker is unsound and can result in use-after-free bugs.","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.","published":"2026-04-09T19:16:25.000Z","lastModified":"2026-10-26T21:10:00.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":1,"severity":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-416"],"affected":["bytecodealliance/wasmtime"],"epss":{"score":0.00117,"percentile":0.01645,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.12%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hfr4-7c6c-48w2","tags":["Mitigation","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hfr4-7c6c-48w2","tags":["Mitigation","Vendor Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-34983","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}