CVE-2026-34983— Wasmtime has a use-after-free bug after cloning `wasmtime::Linker`
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I. Basic Information for CVE-2026-34983
Vulnerability Information
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Vulnerability Title
Wasmtime has a use-after-free bug after cloning `wasmtime::Linker`
Source: NVD (National Vulnerability Database)
Vulnerability Description
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 steps must occur to trigger the bug clone a wasmtime::Linker, drop the original linker instance, use the new, cloned linker instance, resulting in a use-after-free. This vulnerability is fixed in 43.0.1.
Source: NVD (National Vulnerability Database)
CVSS Information
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Type
释放后使用
Source: NVD (National Vulnerability Database)
Vulnerability Title
wasmtime 资源管理错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
wasmtime是Bytecode Alliance开源的一个轻量级WebAssembly运行时。 Wasmtime 43.0.0版本存在资源管理错误漏洞，该漏洞源于克隆wasmtime::Linker时存在缺陷，可能导致释放后重用。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| bytecodealliance | wasmtime | >= 43.0.0, < 43.0.1 | - |
II. Public POCs for CVE-2026-34983
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|---|
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Same Patch Batch · bytecodealliance · 2026-04-09 · 12 CVEs total
| CVE-2026-35195 | Wasmtime has an out-of-bounds write or crash when transcoding component model strings | |
| CVE-2026-35186 | Wasmtime has an improperly masked return value from `table.grow` with Winch compiler backe | |
| CVE-2026-34941 | Wasmtime has a Heap OOB read in component model UTF-16 to latin1+utf16 string transcoding | |
| CVE-2026-34942 | Wasmtime panics when transcoding misaligned utf-16 strings | |
| CVE-2026-34988 | Wasmtime leaks data between pooling allocator instances | |
| CVE-2026-34971 | Wasmtime miscompiled guest heap access enables sandbox escape on aarch64 Cranelift | |
| CVE-2026-34946 | Wasmtime's host panics when Winch compiler executes `table.fill` | |
| CVE-2026-34944 | Wasmtime segfault or unused out-of-sandbox load with `f64x2.splat` operator on x86-64 | |
| CVE-2026-34945 | Wasmtime leaks host data with 64-bit tables and Winch | |
| CVE-2026-34987 | Wasmtime with Winch compiler backend on aarch64 may allow a sandbox-escaping memory access | |
| CVE-2026-34943 | Wasmtime panics when lifting `flags` component value |
IV. Related Vulnerabilities
Same product: wasmtime
- CVE-2026-35195
Wasmtime has an out-of-bounds write or crash when transcodin - CVE-2026-35186
Wasmtime has an improperly masked return value from `table.g - CVE-2026-34988
Wasmtime leaks data between pooling allocator instances - CVE-2026-34987
Wasmtime with Winch compiler backend on aarch64 may allow a - CVE-2026-34971
Wasmtime miscompiled guest heap access enables sandbox escap
Same vendor: bytecodealliance
- CVE-2026-35195
Wasmtime has an out-of-bounds write or crash when transcodin - CVE-2026-35186
Wasmtime has an improperly masked return value from `table.g - CVE-2026-34988
Wasmtime leaks data between pooling allocator instances - CVE-2026-34987
Wasmtime with Winch compiler backend on aarch64 may allow a - CVE-2026-34971
Wasmtime miscompiled guest heap access enables sandbox escap
V. Comments for CVE-2026-34983
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