Medium severity5.0NVD Advisory· Published Apr 9, 2026· Updated Apr 15, 2026
CVE-2026-34983
CVE-2026-34983
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.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
wasmtimecrates.io | >= 43.0.0, < 43.0.1 | 43.0.1 |
Affected products
1- cpe:2.3:a:bytecodealliance:wasmtime:43.0.0:*:*:*:*:rust:*:*
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
4- github.com/advisories/GHSA-hfr4-7c6c-48w2ghsaADVISORY
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hfr4-7c6c-48w2nvdVendor AdvisoryMitigationWEB
- nvd.nist.gov/vuln/detail/CVE-2026-34983ghsaADVISORY
- rustsec.org/advisories/RUSTSEC-2026-0090.htmlghsaWEB
News mentions
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