CVE-2026-126409

LOWCVSS 2/10

Last modified

CVE-2026-126409 is a low-severity vulnerability rated 2/10 on the CVSS scale. 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..

Description

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.

Metrics

Weakness Enumeration

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-126409?
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.
How severe is CVE-2026-126409?
CVE-2026-126409 has a CVSS score of 2/10 (LOW severity).
How do I fix CVE-2026-126409?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST