Default configuration

Wasmtime is an open source runtime for WebAssembly & WASI. Prior to versions 0.34.1 and 0.33.1, there exists a bug in the pooling instance allocator in Wasmtime's runtime where a failure to instantiate an instance for a module that defines an externref global will result in an invalid drop of a...

CVE-2022-23636 Invalid drop of partially-initialized instances in wasmtime

Wasmtime is an open source runtime for WebAssembly & WASI. Prior to versions 0.34.1 and 0.33.1, there exists a bug in the pooling instance allocator in Wasmtime's runtime where a failure to instantiate an instance for a module that defines an externref global will result in an invalid drop of a...

CVE-2022-23636 Invalid drop of partially-initialized instances in wasmtime

Wasmtime is an open source runtime for WebAssembly & WASI. Prior to versions 0.34.1 and 0.33.1, there exists a bug in the pooling instance allocator in Wasmtime's runtime where a failure to instantiate an instance for a module that defines an externref global will result in an invalid drop of a...

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-2021-39218

Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.26.0 and before version 0.30.0 is affected by a memory unsoundness vulnerability. There was an invalid free and out-of-bounds read and write bug when running Wasm that uses externrefs in Wasmtime. To trigger thi...

CVE-2021-39218

Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.26.0 and before version 0.30.0 is affected by a memory unsoundness vulnerability. There was an invalid free and out-of-bounds read and write bug when running Wasm that uses externrefs in Wasmtime. To trigger thi...

Design/Logic Flaw

Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.26.0 and before version 0.30.0 is affected by a memory unsoundness vulnerability. There was an invalid free and out-of-bounds read and write bug when running Wasm that uses externrefs in Wasmtime. To trigger thi...

PYSEC-2021-321

Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.26.0 and before version 0.30.0 is affected by a memory unsoundness vulnerability. There was an invalid free and out-of-bounds read and write bug when running Wasm that uses externrefs in Wasmtime. To trigger thi...

CVE-2021-39216

Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.19.0 and before version 0.30.0 there was a use-after-free bug when passing externrefs from the host to guest Wasm content. To trigger the bug, you have to explicitly pass multiple externrefs from the host to a...

CVE-2021-39219

Wasmtime is an open source runtime for WebAssembly & WASI. Wasmtime before version 0.30.0 is affected by a type confusion vulnerability. As a Rust library the wasmtime crate clearly marks which functions are safe and which are unsafe, guaranteeing that if consumers never use unsafe then it should...

Code injection

Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.19.0 and before version 0.30.0 there was a use-after-free bug when passing externrefs from the host to guest Wasm content. To trigger the bug, you have to explicitly pass multiple externrefs from the host to a...

PYSEC-2021-322

Wasmtime is an open source runtime for WebAssembly & WASI. Wasmtime before version 0.30.0 is affected by a type confusion vulnerability. As a Rust library the wasmtime crate clearly marks which functions are safe and which are unsafe, guaranteeing that if consumers never use unsafe then it should...

PYSEC-2021-320

Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.19.0 and before version 0.30.0 there was a use-after-free bug when passing externrefs from the host to guest Wasm content. To trigger the bug, you have to explicitly pass multiple externrefs from the host to a...

CVE-2021-39218 Out-of-bounds read/write and invalid free with `externref`s and GC safepoints in Wasmtime

Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.26.0 and before version 0.30.0 is affected by a memory unsoundness vulnerability. There was an invalid free and out-of-bounds read and write bug when running Wasm that uses externrefs in Wasmtime. To trigger thi...

CVE-2021-39218

Technical details about CVE-2021-39218 (affected Wasmtime versions 0.26.0–0.30.0, root cause, exploit paths, and fixes) are not provided in the supplied documents. Monitor for official disclosures and patches.

CVE-2021-39219 Wrong type for `Linker`-define functions when used across two `Engine`s

Wasmtime is an open source runtime for WebAssembly & WASI. Wasmtime before version 0.30.0 is affected by a type confusion vulnerability. As a Rust library the wasmtime crate clearly marks which functions are safe and which are unsafe, guaranteeing that if consumers never use unsafe then it should...

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-2021-39216 Use after free passing `externref`s to Wasm in Wasmtime

Wasmtime is an open source runtime for WebAssembly & WASI. In Wasmtime from version 0.19.0 and before version 0.30.0 there was a use-after-free bug when passing externrefs from the host to guest Wasm content. To trigger the bug, you have to explicitly pass multiple externrefs from the host to a...

CVE-2021-39216

Wasmtime (pre-0.30.0) contains a use-after-free when passing multiple externref values from host to guest Wasm, potentially allowing a GC to reclaim the first externref and then reuse it after control returns to Wasm. Affected versions are 0.19.0–0.29.0; upgrading to Wasmtime 0.30.0 fixes the iss...