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.

Attack Vector Network

Attack Complexity High

Privileges Required High

Attack Requirements Present

User Interaction Active

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required High

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
bytecodealliance wasmtime unaffected
Version Status Constraints
47.0.0 affected < 48.0.8
48.0.8 unaffected —
bytecodealliance wasmtime unaffected
Version Status Constraints
49.0.0 affected < 49.0.5
49.0.5 unaffected —
bytecodealliance wasmtime unaffected
Version Status Constraints
50.0.0 affected < 50.0.1
50.0.1 unaffected —

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Project Subscriptions

Vendors Products
Bytecodealliance Subscribe
Wasmtime Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

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

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses