{"id":"UBUNTU-CVE-2026-34983","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.","modified":"2026-05-20T16:25:35.540098488Z","published":"2026-04-09T19:16:00Z","upstream":["CVE-2026-34983"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-34983"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-34983"},{"type":"REPORT","url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hfr4-7c6c-48w2"}],"affected":[{"package":{"name":"rust-wasmtime","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/rust-wasmtime?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["10.0.1+dfsg-7","15.0.1+dfsg-4","16.0.0+dfsg-2","16.0.0+dfsg-3"],"ecosystem_specific":{"binaries":[{"binary_version":"0.103.0+16.0.0+dfsg-3","binary_name":"librust-cranelift-dev"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34983.json"}},{"package":{"name":"rust-wasmtime","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/rust-wasmtime?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["26.0.1+dfsg-3"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-cranelift-dev","binary_version":"0.113.1+26.0.1+dfsg-3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34983.json"}},{"package":{"name":"rust-wasmtime","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/rust-wasmtime?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["26.0.1+dfsg-3","26.0.1+dfsg-4","28.0.1+dfsg-3","29.0.1+dfsg-5","36.0.5+dfsg-1"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-cranelift-dev","binary_version":"0.123.5+36.0.5+dfsg-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34983.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}