JLSEC-2026-1366 wasmtime-wasi: WASI path_open(TRUNCATE) bypasses `FilePerms::WRITE` host restriction

Summary In wasmtime-wasi, when a filesystem preopen is given DirPerms::all and FilePerms::READ without FilePerms::WRITE, this wasmtime-wasi enforced access control mechanism can be bypassed by using the wasip2 descriptor.open-at or wasip1 pathopen interfaces by opening a file with...

CVE-2026-47261

CVE-2026-47261 : Wasmtime-wasi WASI path_open(TRUNCATE) bypasses FilePerms::WRITE host restriction. Root cause: when OpenFlags::TRUNCATE is used, open_mode was not OR-ed with WRITE, allowing a READ-only preopen with DirPerms::all() to bypass access checks via wasip1 path_open or wasip2 descriptor...

CVE-2025-53901: Operation on a Resource after Expiration or Release

Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.4, 33.0.2, and 34.0.2, a bug in Wasmtime's implementation of the WASIp1 set of import functions can lead to a WebAssembly guest inducing a panic in the host embedder. The specific bug is triggered by calling pathopen after calling...

CVE-2024-38358 Symlink bypasses filesystem sandbox in wasmer

Wasmer is a web assembly wasm Runtime supporting WASIX, WASI and Emscripten. If the preopened directory has a symlink pointing outside, WASI programs can traverse the symlink and access host filesystem if the caller sets both oflags::creat and rights::fdwrite. Programs can also crash the runtime ...