Reachable assertion in Wasmtime - #VU155846
Published: October 15, 2026
Vulnerability identifier: #VU155846
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-617
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 a reachable assertion in Wasmtime's store and event loop handling when a previously started call proceeds after a trap has left the store in an inconsistent, poisoned state. A remote user can trigger a trap through misbehaving guest code to cause a denial of service.
Exploitation depends on embedder code allowing pending tasks to continue after the error. User interaction is required.
Affected software
Wasmtime
Remediation
Install security update from vendor's website.
Wasmtime - addressed in versions 48.0.6, 49.0.3