Medium severity · published Oct 29, 2026
CVE-2026-119134
Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 Unbounded Memory Growth via Component-Model Resource Handles
New
6.2
CVSS
–
EPSS
No
On KEV
Description
Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 caps component-model resource handle tables only per component instance and does not charge handle allocations to any ResourceLimiter or StoreLimits. A malicious guest can repeatedly call resource.new and instantiate sub-components to exceed the per-instance cap many times over, causing unbounded host memory growth.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
None
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
before 36.0.18; 37.0.0 before 48.0.6; 49.0.0 before 49.0.3 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-119134
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-119134
vendor-advisory
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-q554-3cjc-rx7p
third-party-advisory
https://www.vulncheck.com/advisories/wasmtime-before-36.0.18-37.0.0-before-48.0.6-and-49.0.0-before-49.0.3-unbounded-memory-growth-via-component-model-resource-handles
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