CVE-2026-27204
Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of WASI host interfaces are susceptible to guest-controlled resource exhaustion on the host. Wasmtime did not appropriately place limits on resource allocations requested by the guests. This serves as a Denial of Service vector. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 have all been released with the fix for this issue. These versions do not prevent this issue in their default configuration to avoid breaking preexisting behaviors. All versions of Wasmtime have appropriate knobs to prevent this behavior, and Wasmtime 42.0.0-and-later will have these knobs tuned by default to prevent this issue from happening. There are no known workarounds for this issue without upgrading. Embedders are recommended to upgrade and configure their embeddings as necessary to prevent possibly-malicious guests from triggering this issue.
EPSS 0.09% · 26.1th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| bytecodealliance | wasmtime | 25.0.0, < 24.0.6, >= 37.0.0, < 40.0.4 |
| crates.io | wasmtime | 37.0.0, 0, 0 |
Timeline
- Feb 24, 2026 CVE Published
- Feb 25, 2026 EPSS Score
- Feb 25, 2026 PoC Published
- Feb 26, 2026 EPSS Score
- Feb 28, 2026 EPSS Score
- Mar 1, 2026 EPSS Score
- Mar 3, 2026 EPSS Score
- Mar 4, 2026 EPSS Score
- Mar 6, 2026 EPSS Score
- Mar 7, 2026 EPSS Score
- Mar 9, 2026 EPSS Score
- Mar 10, 2026 EPSS Score
References
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-852m-cvvp-9p4w url
- https://github.com/bytecodealliance/wasmtime/issues/11552 url
- https://github.com/bytecodealliance/wasmtime/pull/12599 url
- https://docs.rs/wasmtime-wasi/latest/wasmtime_wasi/struct.WasiCtxBuilder.html#method.max_random_size url
- https://docs.rs/wasmtime/latest/wasmtime/component/struct.ResourceTable.html#method.set_max_capacity url
- https://docs.rs/wasmtime/latest/wasmtime/struct.Store.html#method.set_hostcall_fuel url
- https://docs.wasmtime.dev/security-what-is-considered-a-security-vulnerability.html url
- https://nvd.nist.gov/vuln/detail/CVE-2026-27204 advisory
- https://github.com/bytecodealliance/wasmtime package
- https://rustsec.org/advisories/RUSTSEC-2026-0020.html url