CVE-2026-34943
High · 7.5CVSS
7.5
EPSS
0.4%
Published
Apr 9, 2026
CISA due date
—
The record
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits should be ignored but Wasmtime will panic when this value is lifted. This panic only affects wasmtime's implementation of lifting into Val, not when using the flags! macro. This additionally only affects flags-typed values which are part of a WIT interface. This has the risk of being a guest-controlled panic within the host which Wasmtime considers a DoS vector. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| crates.io | wasmtime | 0 | 24.0.7 |
| crates.io | wasmtime | 0.0.0-0 | 24.0.7 |
| crates.io | wasmtime | 25.0.0 | 36.0.7 |
| crates.io | wasmtime | 37.0.0 | 42.0.2 |
| crates.io | wasmtime | 43.0.0 | 43.0.1 |
| openSUSE:Tumbleweed | tree-sitter | 0 | 0.26.8-2.1 |
Related vulnerabilities
- RUSTSEC-2026-0085 Panic when lifting `flags` component value Same vulnerability
- CVE-2026-44216 Wasmtime is a runtime for WebAssembly. Also affects wasmtime
- RUSTSEC-2026-0114 Panic when allocating a table exceeding the size of the host's address space Also affects wasmtime
- CVE-2026-34988 Wasmtime is a runtime for WebAssembly. Also affects wasmtime
- CVE-2026-35195 Wasmtime is a runtime for WebAssembly. Also affects wasmtime
- CVE-2026-34987 Wasmtime is a runtime for WebAssembly. Also affects wasmtime
- CVE-2026-35186 Wasmtime is a runtime for WebAssembly. Also affects wasmtime
- CVE-2026-34971 Wasmtime is a runtime for WebAssembly. Also affects wasmtime