Vulnerability DatabaseCVE-2026-126409
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CVE-2026-126409
Published:November 13, 2026
Updated:November 13, 2026
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.
Affected Packages
https://github.com/bytecodealliance/wasmtime.git (GITHUB):
Affected version(s) >=v50.0.0-rc.1 <v50.0.1
Fix Suggestion:
Update to version v50.0.1
https://github.com/bytecodealliance/wasmtime.git (GITHUB):
Affected version(s) >=v49.0.0-rc.1 <v49.0.5
Fix Suggestion:
Update to version v49.0.5
https://github.com/bytecodealliance/wasmtime.git (GITHUB):
Affected version(s) >=v22.0.0 <v48.0.8 || >=v23.0.0 <v48.0.8 || >=v24.0.0 <v48.0.8 || >=v25.0.0 <v48.0.8 || >=v26.0.0 <v48.0.8 || =v27.0.0 <v48.0.8 || >=v28.0.0 <v48.0.8 || >=v29.0.0 <v48.0.8 || >=v30.0.0 <v48.0.8 || =v31.0.0 <v48.0.8 || >=v32.0.0 <v48.0.8 || >=v33.0.0 <v48.0.8 || >=v34.0.0 <v48.0.8 || =v35.0.0 <v48.0.8 || >=v36.0.0 <v48.0.8 || >=v37.0.0 <v48.0.8 || >=v38.0.1 <v48.0.8 || >=v39.0.0 <v48.0.8 || >=v40.0.0 <v48.0.8 || >=v41.0.0 <v48.0.8 || >=v42.0.0 <v48.0.8 || >=v43.0.0 <v48.0.8 || >=v44.0.0 <v48.0.8 || >=v45.0.0 <v48.0.8 || >=v46.0.0 <v48.0.8 || >=v47.0.0 <v48.0.8 || >=v48.0.0 <v48.0.8
Fix Suggestion:
Update to version v48.0.8
wasmtime (RUST):
Affected version(s) >=45.0.0 <48.0.8 || >=48.0.0 <48.0.8 || >=42.0.0 <48.0.8 || >=30.0.0 <48.0.8 || >=26.0.0 <48.0.8 || >=39.0.0 <48.0.8 || >=38.0.0 <48.0.8 || =27.0.0 <48.0.8 || >=32.0.0 <48.0.8 || >=40.0.0 <48.0.8 || >=29.0.0 <48.0.8 || >=34.0.0 <48.0.8 || >=24.0.0 <48.0.8 || >=33.0.0 <48.0.8 || >=25.0.0 <48.0.8 || =31.0.0 <48.0.8 || >=28.0.0 <48.0.8 || >=37.0.0 <48.0.8 || >=22.0.0 <48.0.8 || >=41.0.0 <48.0.8 || =35.0.0 <48.0.8 || >=43.0.0 <48.0.8 || >=36.0.0 <48.0.8 || >=44.0.0 <48.0.8 || >=47.0.0 <48.0.8 || >=46.0.0 <48.0.8 || >=23.0.0 <48.0.8
Fix Suggestion:
Update to version 48.0.8
wasmtime (RUST):
Affected version(s) >=49.0.0-rc.1 <49.0.5
Fix Suggestion:
Update to version 49.0.5
wasmtime (RUST):
Affected version(s) >=50.0.0-rc.1 <50.0.1
Fix Suggestion:
Update to version 50.0.1
Related Resources (2)
https://www.vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.8-cross-engine-type-confusion-via-structtype-supertype
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-qw58-7h65-crq2
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CVSS v4
Base Score:
1.8
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
PRESENT
Privileges Required
HIGH
User Interaction
ACTIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
2
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
HIGH
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
Access of Resource Using Incompatible Type
CWE-843