Uncontrolled Memory Allocation in Wasmtime - #VU144567
Published: August 21, 2026
Vulnerability identifier: #VU144567
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-789
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to memory allocation with excessive size value in WASIp3 file and HTTP streams when writing to streams with a guest-specified-length buffer. A remote user can provide stream data with a guest-controlled length to cause a denial of service.
WASIp3 was not enabled by default in versions prior to 46.0.0. User interaction is required.
Affected software
Wasmtime
Remediation
Install security update from vendor's website.
Wasmtime - addressed in versions 46.0.3, 47.0.4