4.8
MediumCVSS 3.1 · from VulnCheck
CVE-2026-119140
Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Host Panic via thread.yield
wasmtime · CWE-372 · CWE-372Affectedwasmtime
FixUpdate to 48.0.6, 49.0.3 or newer
PublishedOct 29, 15:58 · VulnCheck
ScoredOct 29 · 4.8 · VulnCheck
Exploit code publicNone known · checked 21:18 UTC
ExploitedNone known · CISA KEV checked 22:08 UTC
What we know
No known exploitation. CISA KEV, checked 22:08 UTC.
No public exploit code known. Exploit-DB, Metasploit, Nuclei, checked 21:18 UTC.
An attacker needs network access and an account. CVSS: network, low privileges.
It only works under certain conditions, which makes it harder to pull off. CVSS: high attack complexity.
Someone has to open, click or run something first. CVSS: user interaction required.
A successful attack can take the service down. CVSS impact.
Description
Wasmtime 46.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains a denial of service vulnerability that allows malicious components to panic the host via thread.yield in start functions. Attackers can supply a component whose start function calls an async-lowered import then thread.yield, causing an undisposed fiber drop that crashes embedders.
From VulnCheck
Affected and fixed versions
ProductAffectedFixed inwasmtime46.0.0 – before 48.0.648.0.6wasmtimeNot affected48.0.6wasmtime49.0.0 – before 49.0.349.0.3wasmtimeNot affected49.0.3
Exploit code
Exploit-DBnone knownMetasploitnone knownNucleinone known