{"id":"CVE-2026-104855","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-104855","generatedAt":"2026-10-28T01:01:29.809Z","title":"From 46.0.0 until 46.0.2 and 47.0.3, fuel and epoch preemption checks inside bulk operations including memory.copy, table.grow, and array.copy can expose invalid intermediate state when an embedder mutates a Store in Store::epoch_deadline_callback or…","description":"Wasmtime is a runtime for WebAssembly. From 46.0.0 until 46.0.2 and 47.0.3, fuel and epoch preemption checks inside bulk operations including memory.copy, table.grow, and array.copy can expose invalid intermediate state when an embedder mutates a Store in Store::epoch_deadline_callback or continues using a Store after cancellation or a trap. A cancelled non-nullable table growth can leave null elements, linear-memory growth during memory.copy can invalidate retained raw pointers, and callback-triggered garbage collection during array.copy can invalidate GC pointers, resulting in a crash, invalid memory access, or GC heap corruption. Embeddings whose callbacks only access the host data in Store<T>, and embeddings that discard a Store after timeout or epoch deadline, are not affected. This issue is fixed in versions 46.0.2 and 47.0.3.","published":"2026-10-02T18:17:02.000Z","lastModified":"2026-10-06T17:17:16.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":2,"severity":"LOW","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/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-362"],"affected":[],"epss":{"score":0.00276,"percentile":0.19866,"date":"2026-10-26","history":[{"date":"2026-10-03","score":0.00276,"percentile":0.18222}]},"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 (0.28%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-02T18:17:02.000Z","detail":{"score":"2.0","severity":"LOW","publishedAt":"2026-10-02T18:17:02.083Z"},"summary":"New CVE, low severity (CVSS 2.0)."}],"references":[{"url":"https://github.com/bytecodealliance/wasmtime/commit/3ebfbe5af4927c157d6fcaca42b8dbb6d17b73fb","source":"security-advisories@github.com"},{"url":"https://github.com/bytecodealliance/wasmtime/commit/99b0bc39d447317a4102c056081c83a9a84a46e0","source":"security-advisories@github.com"},{"url":"https://github.com/bytecodealliance/wasmtime/commit/a3eb27af01ba5a30320a90ea1405059cdfedd353","source":"security-advisories@github.com"},{"url":"https://github.com/bytecodealliance/wasmtime/pull/14041","source":"security-advisories@github.com"},{"url":"https://github.com/bytecodealliance/wasmtime/pull/14043","source":"security-advisories@github.com"},{"url":"https://github.com/bytecodealliance/wasmtime/pull/14045","source":"security-advisories@github.com"},{"url":"https://github.com/bytecodealliance/wasmtime/releases/tag/v46.0.2","source":"security-advisories@github.com"},{"url":"https://github.com/bytecodealliance/wasmtime/releases/tag/v47.0.3","source":"security-advisories@github.com"},{"url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-2hw9-mc66-jc2q","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-104855","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."}