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.
Advisories

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Fixes

Solution

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Workaround

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History

Fri, 13 Nov 2026 09:45:00 +0000

Type Values Removed Values Added
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.
Title Wasmtime 47.0.0 before 48.0.8 Cross-Engine Type Confusion via StructType Supertype
First Time appeared Bytecodealliance
Bytecodealliance wasmtime
Weaknesses CWE-843
CPEs cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:*
Vendors & Products Bytecodealliance
Bytecodealliance wasmtime
References
Metrics cvssV3_1

{'score': 2, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 1.8, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-13T09:35:42.234Z

Reserved: 2026-11-10T21:34:05.396Z

Link: CVE-2026-126409

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-13T10:17:46.013

Modified: 2026-11-13T10:17:46.150

Link: CVE-2026-126409

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses