CVE-2026-126409

CVSS 2.0 (low) · published 2026-11-13

Wasmtime 47.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains a cross-engine type confusion vulnerability because StructType::with_finality_and_supertype does not validate that the supplied supertype belongs to the same Engine. Embedders using multiple engines that create a GC struct type with another engine's supertype can trigger runtime panics or GC heap corruption, causing denial of service; guest WebAssembly cannot trigger it.

Weakness: CWE-843

Source: NVD CVE-2026-126409

References

• https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-qw58-7h65-crq2
• https://www.vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.8-cross-engine-type-confusion-via-structtype-supertype

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