Bug 2456992 (CVE-2026-34983) - CVE-2026-34983 wasmtime: Wasmtime: Use-after-free due to unsound linker cloning
Summary: CVE-2026-34983 wasmtime: Wasmtime: Use-after-free due to unsound linker cloning
Keywords:
Status: NEW
Alias: CVE-2026-34983
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2457168
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-04-09 19:01 UTC by OSIDB Bzimport
Modified: 2026-04-09 22:46 UTC (History)
0 users

Fixed In Version:
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Description OSIDB Bzimport 2026-04-09 19:01:30 UTC 
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.
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