Description
Wasmtime before 36.0.20, 37.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 allocates untracked host memory when a component receives a borrow of a resource it defines itself, bypassing the per-store handle limit. A malicious guest component can repeatedly transfer such borrowed resources to consume arbitrary host memory, causing denial of service.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| bytecodealliance | wasmtime | < 36.0.20, 37.0.0 – < 48.0.8, 49.0.0 – < 49.0.5, 50.0.0 – < 50.0.1 | 36.0.20 |
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 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| crates.io | wasmtime | >= 0.0.0-0, < 36.0.20 · >= 37.0.0, < 48.0.8 · >= 49.0.0, < 49.0.5 · >= 50.0.0, < 50.0.1 | 36.0.20, 48.0.8, 49.0.5, 50.0.1 | RUSTSEC-2026-0424 |
References
- GitHub Security Advisory (GHSA-6fr9-xmw9-5352) vendor-advisory
- VulnCheck Advisory: Wasmtime before 36.0.20 Denial of Service via Borrowed Resource Transfer third-party-advisory