JLSEC-2026-1358 Wasmtime has host data leakage with 64-bit tables and Winch

Impact Wasmtime's Winch compiler contains a bug where a 64-bit table, part of the memory64 proposal of WebAssembly, incorrectly translated the table.size instruction. This bug could lead to disclosing data on the host's stack to WebAssembly guests. The host's stack can possibly contain sensitive...

wasmtime: Wasmtime: Denial of Service via large WebAssembly table allocation

A flaw was found in Wasmtime, a runtime for WebAssembly. A remote attacker could exploit an arithmetic overflow vulnerability by instantiating a WebAssembly module or component that attempts to allocate an extremely large table using the WebAssembly memory64 proposal. This flaw causes Wasmtime to...

Wasmtime has host data leakage with 64-bit tables and Winch

Impact Wasmtime's Winch compiler contains a bug where a 64-bit table, part of the memory64 proposal of WebAssembly, incorrectly translated the table.size instruction. This bug could lead to disclosing data on the host's stack to WebAssembly guests. The host's stack can possibly contain sensitive...

CVE-2026-34945 Wasmtime leaks host data with 64-bit tables and Winch

Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Winch compiler contains a bug where a 64-bit table, part of the memory64 proposal of WebAssembly, incorrectly translated the table.size instruction. This bug could lead to disclosing data on the...

wasmtime 安全漏洞

Wasmtime is a lightweight WebAssembly runtime open source by the Bytecode Alliance. Versions of Wastime prior to 25.0.0, 36.0.7, 42.0.2, and 43.0.1 contained security vulnerabilities. These vulnerabilities stemmed from the Winch compiler incorrectly translating the table.size instruction, which i...