CVE-2024-51745

Wasmtime on Windows had a sandbox bypass where filenames with superscript digits (e.g., COM¹, LPT⁰) were not blocked, allowing untrusted Wasm code with filesystem access to reach devices and peripherals via special device filenames. Affected software: Wasmtime’s Windows filesystem sandbox. Root c...

CVE-2025-53901

Wasmtime WASI (wasmtime-wasi) contains a bug in the WASIp1 import implementation. Prior to 24.0.4, 33.0.2, and 34.0.2, calling fd_renumber followed by path_open can cause a WebAssembly guest to panic the host (embedder). The panic results from a corrupt state in fd_renumber when a second open fil...

CVE-2022-23636

CVE-2022-23636 affects Wasmtime prior to 0.34.1 and 0.33.1, due to a bug in the pooling instance allocator that can cause an invalid drop of a VMExternRef when a module defines an externref global and instance creation fails. The vulnerability depends on specific conditions (e.g., mprotect/Virtua...

CVE-2021-39219

Technical details about CVE-2021-39219 are not publicly provided in the connected documents. Monitor for updates from official advisories; the supplied sources do not enumerate affected products/versions or fixes beyond the initial description.

CVE-2022-31104

CVE-2022-31104 concerns Wasmtime’s x86_64 SIMD implementation. Two Cranelift lowering bugs affected i8x16.swizzle and select for v128 inputs: swizzle overwrote the mask input register, potentially corrupting a constant; and select incorrectly handled 128‑bit vectors when the condition was 0, movi...

CVE-2022-31169

CVE-2022-31169 affects Wasmtime’s Cranelift codegen on AArch64. A miscompilation in constant division may place incorrect values in registers due to sign/zero-extension rules, impacting WebAssembly sandbox correctness. Affected: Wasmtime prior to 0.38.2 and Cranelift prior to 0.85.2; fixed in Was...

CVE-2022-39392

CVE-2022-39392 affects Wasmtime’s pooling instance allocator when InstanceLimits::memory_pages is set to zero. In this configuration, the virtual memory mapping for WebAssembly memories can fail to meet safety requirements, allowing out-of-bounds reads/writes to access memory outside the wasm san...

CVE-2022-39393

Wasmtime vulnerability CVE-2022-39393: prior to versions 2.0.2 and 1.0.2, a bug in the pooling instance allocator can cause the initial heap snapshot of a prior instance to be visible to the next instance when reusing linear memory. This data leakage between instances can lead to information expo...

CVE-2022-39394

CVE-2022-39394 affects Wasmtime prior to 2.0.2: a mismatch in the wasmtime_trap_code C API implementation can cause a 4-byte write into a 1-byte caller buffer, writing three zero bytes beyond the provided location. The issue is fixed in Wasmtime 2.0.2. Workaround: cast a 4-byte buffer to a 1-byte...

CVE-2023-30624

Wasmtime CVE-2023-30624 concerns an LLVM-level undefined behavior in per-instance state management (VMContext) of the Wasmtime runtime. The issue occurs in Wasmtime versions prior to 6.0.2, 7.0.1, and 8.0.1 and arises when unsafe code mutates VMContext data via methods using &self, which can lead...

CVE-2026-27204

CVE-2026-27204 involves Wasmtime’s WASI host interfaces, where guest code could exhaust host resources due to insufficient limits on resource allocations. Affected versions prior to fixes include 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0. The fixes are released in Wasmtime 24.0.6, 36.0.6, 40.0.4...

CVE-2026-34941

Wasmtime (WebAssembly runtime) contains a heap OOB read during transcoding of UTF-16 to the latin1+utf16 component-model encoding. The bug stems from validating the input length by code units instead of by byte length, causing reads beyond the WebAssembly linear memory during bounds checking. In ...

CVE-2026-34942

Wasmtime VM exposes a DoS risk due to a panic-triggering path when transcoding strings into utf16/latin1+utf16. Root cause: alignment verification for reallocated strings was improper, allowing unaligned pointers to be passed to the host by a malicious guest. Affected versions prior to fixed rele...

CVE-2026-27572

Wasmtime (WebAssembly runtime) is affected by CVE-2026-27572 in the wasi:http/types.fields implementation. Prior to patched releases (Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0), the wasmtime-wasi-http crate uses a data structure that panics when the headers field set becomes excessively...

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-2026-35195

The CVE-2026-35195 vulnerability affects Wasmtime (WebAssembly runtime) where the guest component’s realloc return value is not validated during transcoding of component-model strings. This can allow a guest to cause the host to write arbitrary transcoded string bytes to an arbitrary address up t...

CVE-2026-34943

Wasmtime (WebAssembly runtime) has a vulnerability where lifting a flags-typed component-model value with Val can panic if bits outside the allowed flags set are present. Affected versions before fixes include 24.0.7, 36.0.7, 42.0.2, and 43.0.1; the panic occurs in Wasmtime’s Val lifting (not in ...

CVE-2026-34944

Wasmtime (WebAssembly runtime) prior to versions 24.0.7, 36.0.7, 42.0.2, and 43.0.1 on x86-64 with SSE3 disabled could compile f64x2.splat via Cranelift in a way that loads 8 extra bytes. When signals-based traps are disabled this may cause an uncaught segfault from unmapped guard pages. With gua...