{"id":"GHSA-jxhv-7h78-9775","revision":"9717c3ca3d744e6c85f431a22cd4c4e5","records":[{"revision":"9717c3ca3d744e6c85f431a22cd4c4e5","observedAt":"2026-10-24T13:19:54.901+00:00","statement":{"source":"osv","id":"GHSA-jxhv-7h78-9775","aliases":["CVE-2026-34942","RUSTSEC-2026-0092"],"title":"Wasmtime: Panic when transcoding misaligned utf-16 strings","description":"### Impact\n\nWasmtime's implementation of transcoding strings into the Component Model's `utf16` or `latin1+utf16` encodings improperly verified the alignment of reallocated strings. This meant that unaligned pointers could be passed to the host for transcoding which would trigger a host panic. This panic is possible to trigger from malicious guests which transfer very specific strings across components with specific addresses. \n\nHost panics are considered a DoS vector in Wasmtime as the panic conditions are controlled by the guest in this situation.\n\n### Patches\n\nWasmtime 24.0.7, 36.0.7, 42.0.2, and 43.0.1 have been issued to fix this bug. Users are recommended to update to these patched versions of Wasmtime.\n\n### Workarounds\n\nThere is no workaround for this bug. Hosts are recommended to updated to a patched version of Wasmtime.","state":0,"publishedAt":"2026-04-09T20:22:12+00:00","modifiedAt":"2026-09-10T03:50:44.7075583+00:00","affected":[{"ecosystem":"crates.io","name":"wasmtime","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"24.0.7"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"crates.io","name":"wasmtime","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"25.0.0"},{"kind":"fixed","version":"36.0.7"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"crates.io","name":"wasmtime","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"37.0.0"},{"kind":"fixed","version":"42.0.2"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"crates.io","name":"wasmtime","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"43.0.0"},{"kind":"fixed","version":"43.0.1"}]}],"versions":["43.0.0"],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":null,"severity":null},{"system":"CVSS_V4","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-jxhv-7h78-9775","https://nvd.nist.gov/vuln/detail/CVE-2026-34942","https://github.com/bytecodealliance/wasmtime","https://rustsec.org/advisories/RUSTSEC-2026-0092.html"],"sourceUrl":"https://github.com/advisories/GHSA-jxhv-7h78-9775","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-jxhv-7h78-9775","identifiers":["GHSA-jxhv-7h78-9775","CVE-2026-34942","RUSTSEC-2026-0092"]},"retained":false,"historicalAffected":[]}],"coverage":[]}