Description
Wasmtime is a runtime for WebAssembly. From 46.0.0 until 48.0.7 and 49.0.4, lowering a host-created component-model stream or future into a guest can omit a required payload-type check after the value passes through guest code and returns through StreamAny, FutureAny, Val::Stream, Val::Future, or an equivalent typed reader. A malicious guest that controls exported function types or returned values can cause the host to pass the type-erased value to a guest expecting a different payload type, which panics the Wasmtime host. This issue is fixed in versions 48.0.7 and 49.0.4.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| bytecodealliance | wasmtime | >= 46.0.0, < 48.0.7, >= 49.0.0, < 49.0.4 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | rust-wasmtime | No fix yet | — |
| Ubuntu 26.04 LTS | rust-wasmtime | No fix yet | — |
| Ubuntu 24.04 LTS | rust-wasmtime | No fix yet | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | wasmcloud | 2.10.3-r3 | — |
| Wolfi rolling | yara-x | 1.22.0-r1 | — |
| Wolfi rolling | zed | 1.24.4-r1 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| crates.io | wasmtime | >= 46.0.0, < 48.0.7 | 48.0.7 | GHSA-9pvw-hwfg-92h5 |
| crates.io | wasmtime | >= 49.0.0, < 49.0.4 | 49.0.4 | GHSA-9pvw-hwfg-92h5 |
| crates.io | wasmtime | >= 46.0.0, < 48.0.7 · >= 49.0.0, < 49.0.4 | 48.0.7, 49.0.4 | RUSTSEC-2026-0378 |
References
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-9pvw-hwfg-92h5
- https://github.com/bytecodealliance/wasmtime/pull/14819
- https://github.com/bytecodealliance/wasmtime/pull/14820
- https://github.com/bytecodealliance/wasmtime/pull/14827
- https://github.com/bytecodealliance/wasmtime/commit/222ff3a65dab9aa7011f8c246937751a0bac5abd
- https://github.com/bytecodealliance/wasmtime/commit/48dacc76241f06088e79f3ce1b17642f2f7bf158
- https://github.com/bytecodealliance/wasmtime/commit/994549891c8a706cb4f2809f9d17b9f67b31e618
- https://github.com/bytecodealliance/wasmtime/releases/tag/v48.0.7
- https://github.com/bytecodealliance/wasmtime/releases/tag/v49.0.4