CVE-2026-119133
Published:October 29, 2026
Updated:October 30, 2026
Wasmtime 47.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a memory misalignment flaw in VMContext layout that causes undefined behavior when modules contain an odd number of exception tags. A WebAssembly module with an odd tag count misaligns subsequent host fields in embedders with exceptions enabled, although no exploitation path is currently known.
Affected Packages
https://github.com/bytecodealliance/wasmtime.git (GITHUB):
Affected version(s) >=v47.0.0 <v48.0.6 || >=v48.0.0 <v48.0.6Fix Suggestion:
Update to version v48.0.6https://github.com/bytecodealliance/wasmtime.git (GITHUB):
Affected version(s) =v50.0.0-rc.1 <v50.0.0Fix Suggestion:
Update to version v50.0.0https://github.com/bytecodealliance/wasmtime.git (GITHUB):
Affected version(s) >=v49.0.0-rc.1 <v49.0.3Fix Suggestion:
Update to version v49.0.3wasmtime-environ (RUST):
Affected version(s) >=49.0.0-rc.1 <49.0.3Fix Suggestion:
Update to version 49.0.3wasmtime-environ (RUST):
Affected version(s) >=47.0.0 <48.0.6 || >=48.0.0 <48.0.6Fix Suggestion:
Update to version 48.0.6wasmtime-environ (RUST):
Affected version(s) =50.0.0-rc.1 <50.0.0Fix Suggestion:
Update to version 50.0.0Related Resources (2)
Do you need more information?
Contact UsCVSS v4
Base Score:
2.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
PRESENT
Privileges Required
LOW
User Interaction
PASSIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
2.6
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Reliance on Undefined, Unspecified, or Implementation-Defined Behavior