CVE-2022-31146
highpriority · track · 35EPSS 0.013 · 69 %ileEUUSEPSS · scored 2026-10-27
Wasmtime is a standalone runtime for WebAssembly. There is a bug in the Wasmtime's code generator, Cranelift, where functions using reference types may be incorrectly missing metadata required for runtime garbage collection. This means that if a GC happens at runtime then the GC pass will mistakenly think these functions do not have live references to GC'd values, reclaiming them and deallocating them. The function will then subsequently continue to use the values assuming they had not been GC'd, leading later to a use-after-free. This bug was introduced in the migration to the `regalloc2` register allocator that occurred in the Wasmtime 0.37.0 release on 2022-05-20. This bug has been patched and users should upgrade to Wasmtime version 0.38.2. Mitigations for this issue can be achieved by disabling the reference types proposal by passing `false` to `wasmtime::Config::wasm_reference_types` or downgrading to Wasmtime 0.36.0 or prior.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.4–8.8
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (7)
Products and version ranges known to be affected.
- bytecodealliance cranelift-codegen0.84.0 → 0.85.2nvdUScpe:2.3:a:bytecodealliance:cranelift-codegen:*:*:*:*:*:*:*:*
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-5fhj-g3p3-pq9gWasmtime vulnerable to Use After Free with `externref`s2022-07-20ghsa · osvUS
There is a bug in Wasmtime's code generator, Cranelift, where functions using reference types may be incorrectly missing metadata required for runtime garbage collection (GC). This means that if a GC happens at runtime then the collector will mistakenly think some Wasm stack frames do not have live references to garbage collected values and therefore reclaim and deallocate them. The function can then subsequently continue to use the values, leading later to use-after-free bugs. This bug was introduced in Cranelift's migration to the `regalloc2` register allocator in the Wasmtime 0.37.0 release on 2022-05-20. This bug has been patched and users should upgrade to Wasmtime version 0.38.2. Mitigations for this issue can be achieved by doing one of: * Disabling the reference types proposal by passing `false` to [`wasmtime::Config::wasm_reference_types`](https://docs.rs/wasmtime/0.38.0/wasmtime/struct.Config.html#method.wasm_reference_types). * Downgrading to Wasmtime 0.36.0 or prior.
- RUSTSEC-2022-0100Use After Free with `externref`s in Wasmtime2022-07-12vendor · osvUS
This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-5fhj-g3p3-pq9g. For more information see the GitHub-hosted security advisory.
also known as (5)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2022-31146/cnnvd
- https://github.com/WebAssembly/reference-typescnnvd
- https://github.com/bytecodealliance/wasmtime/cnnvd
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-5fhj-g3p3-pq9gcnnvd
- https://github.com/WebAssembly/reference-typesenisa_euvd
- https://github.com/bytecodealliance/wasmtime/enisa_euvd
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-5fhj-g3p3-pq9genisa_euvd
- https://github.com/WebAssembly/reference-typesThird Party Advisorynvd
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