Use-after-free bug after cloning `wasmtime::Linker`

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hfr4-7c6c-48w2 For more information see the GitHub-hosted security advisory...

Data leakage between pooling allocator instances

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-6wgr-89rj-399p For more information see the GitHub-hosted security advisory...

WasmTime buffer error vulnerability

Wasmtime is a lightweight WebAssembly runtime open source by the Bytecode Alliance. Versions of Wastime prior to 36.0.7, 42.0.2, and 43.0.1 contained a buffer error vulnerability. This vulnerability stemmed from a flaw in the Winch compiler backend, which could allow guest Wasm access to host...

CVE-2026-34987: Out-of-bounds Read

Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime with its Winch baseline non-default compiler backend may allow properly constructed guest Wasm to access host memory outside of its linear-memory sandbox. This vulnerability requires use of the Winch...

WasmTime security vulnerability

Wasmtime is a lightweight WebAssembly runtime open source by the Bytecode Alliance. Versions prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1 of Wastime contain security vulnerabilities. These vulnerabilities arise when using the Val type promotion feature to increase values of component models. If bi...

WasmTime security vulnerability

Wasmtime is a lightweight WebAssembly runtime open source by the Bytecode Alliance. Versions prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1 of Wastime have security vulnerabilities. These vulnerabilities arise from the use of Cranelift for compiling f64x2.splat WebAssembly instructions on x86-64...

WasmTime security vulnerability

Wasmtime is a lightweight WebAssembly runtime open source by the Bytecode Alliance. Versions of Wastime prior to 25.0.0, 25.0.2, 42.0.2, and 43.0.1 contained security vulnerabilities. These vulnerabilities stemmed from the fact that compiling the table.fill instruction could lead to a...

WasmTime resource management error vulnerability

Wasmtime is a lightweight WebAssembly runtime open source by the Bytecode Alliance. Version 43.0.0 of Wastime contains a resource management vulnerability. This vulnerability stems from a flaw in cloning wastim::Linker, which may lead to reuse after reclamation...

CVE-2026-34983: Use After Free

Wasmtime is a runtime for WebAssembly. In 43.0.0, cloning a wasmtime::Linker is unsound and can result in use-after-free bugs. This bug is not controllable by guest Wasm programs. It can only be triggered by a specific sequence of embedder API calls made by the host. Specifically, the following...

CVE-2026-34946: Always-Incorrect Control Flow Implementation

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 vulnerability where the compilation of the table.fill instruction can result in a host panic. This means that a valid guest can be compiled with Winch, on any architecture...

CVE-2026-34945: Incorrect Conversion between Numeric Types

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...

CVE-2026-34944: Uncaught Exception

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, On x86-64 platforms with SSE3 disabled Wasmtime's compilation of the f64x2.splat WebAssembly instruction with Cranelift may load 8 more bytes than is necessary. When signals-based-traps are disabled this can resul...

PT-2026-31687

Name of the Vulnerable Software and Affected Versions Wasmtime versions 25.0.0 through 36.0.6, 42.0.2, and 43.0.1 Description Wasmtime, a runtime for WebAssembly, contains an issue where the compilation of the table.fill instruction using the Winch compiler can lead to a host panic. A valid guest...

PT-2026-31680

Name of the Vulnerable Software and Affected Versions Wasmtime versions prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1 Description Wasmtime contains an issue where transcoding a UTF-16 string to the latin1+utf16 component-model encoding incorrectly validates the byte length of the input string durin...

PT-2026-31681

Name of the Vulnerable Software and Affected Versions Wasmtime versions prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1 Description Wasmtime's implementation of transcoding strings into the Component Model's utf16 or latin1+utf16 encodings did not properly verify the alignment of reallocated strings...

Linux Distros Unpatched Vulnerability : CVE-2026-34971

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Wasmtime is a runtime for WebAssembly. From 32.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Cranelift compilation backend contains a bug on aarch64 when...

PT-2026-31689

Wasmtime is a runtime for WebAssembly. In 43.0.0, cloning a wasmtime::Linker is unsound and can result in use-after-free bugs. This bug is not controllable by guest Wasm programs. It can only be triggered by a specific sequence of embedder API calls made by the host. Specifically, the following...

PT-2026-31685

Name of the Vulnerable Software and Affected Versions Wasmtime versions prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1 Description Wasmtime, a runtime for WebAssembly, may experience an uncaught segfault on x86-64 platforms with SSE3 disabled when compiling the f64x2.splat WebAssembly instruction wi...

CVE-2026-35195: Out-of-bounds Write

Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime's implementation of transcoding strings between components contains a bug where the return value of a guest component's realloc is not validated before the host attempts to write through the pointer. This...

CVE-2026-34988: Improper Restriction of Operations within the Bounds of a Memory Buffer

Wasmtime is a runtime for WebAssembly. From 28.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's implementation of its pooling allocator contains a bug where in certain configurations the contents of linear memory can be leaked from one instance to the next. The implementation of resetting the...