Medium severity · published Oct 29, 2026
CVE-2026-119136
Wasmtime 42.0.0 before 48.0.6 and 49.0.0 before 49.0.3 Async-Entrypoint Enforcement Bypass
New
4.8
CVSS
–
EPSS
No
On KEV
Description
Wasmtime 42.0.0 before 48.0.6 and 49.0.0 before 49.0.3 contains insufficient checks in Store when mixing async-style and sync-style WebAssembly calls. Embedders re-entering WebAssembly via sync APIs from host functions called asynchronously can trigger runtime panics or unsound cross-thread movement of !Send host variables.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WA
wasmtime · bytecodealliance
42.0.0 before 48.0.6; 49.0.0 before 49.0.3 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-119136
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-119136
vendor-advisory
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-vcg5-q8m5-8379
third-party-advisory
https://www.vulncheck.com/advisories/wasmtime-42.0.0-before-48.0.6-and-49.0.0-before-49.0.3-async-entrypoint-enforcement-bypass
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