Missing Release of Resource after Effective Lifetime in Wasmtime - CVE-2026-54786
Published: August 1, 2026
Vulnerability identifier: #VU140661
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-54786
CWE-ID: CWE-772
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 improper resource shutdown in WASIp1 `fd_renumber` implementation when renumbering file descriptors. A remote user can repeatedly invoke `fd_renumber` after obtaining file descriptors to cause a denial of service.
Only the native WASIp1 implementation is affected, and exploitation requires a runtime that exposes `fd_renumber` and allows acquisition of file descriptors such as by opening files.
Affected software
Wasmtime
How to mitigate CVE-2026-54786
Install security update from vendor's website.
Wasmtime - addressed in versions 3.0.0, 24.0.10, 36.0.11, 44.0.0, 45.0.2