CVE-2026-126409

Wasmtime 47.0.0 before 48.0.8 Cross-Engine Type Confusion via StructType Supertype

Published Nov 13, 2026 CVSS 4.0 · 1.8 Low EPSS n/a KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 13, 2026, 9:35 AM
Reserved
Nov 10, 2026, 9:34 PM
Status
Deferred
Published
Nov 13, 2026, 10:17 AM
Modified
Nov 13, 2026, 10:17 AM