Vulnerability record/PUBLISHED/Published Nov 13, 2026 09:35:43 UTC

CVE-2026-126407

Wasmtime before 36.0.20, 37.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 allocates untracked host memory when a component receives a borrow of a resource it defines itself, bypassing the per-store handle limit. A malicious guest component can repeatedly transfer such borrowed resources to consume arbitrary host memory, causing denial of service.

Base score5.9/ 10

SeverityMediumCVSS 4.0

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes

Base severityMedium

Attack vectorNetworkAV

Attack complexityLowAC

Attack requirementsPresentAT

Privileges requiredLowPR

User interactionPassiveUI

Vulnerable system confidentialityNoneVC

Vulnerable system integrityNoneVI

Vulnerable system availabilityHighVA

Subsequent system confidentialityNoneSC

Subsequent system integrityNoneSI

Subsequent system availabilityNoneSA

CVSS vector stringCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering AuthorityVulnCheck

Last updatedNov 13, 2026 15:55:30 UTC

PublishedNov 13, 2026 09:35:43 UTC

ReservedNov 10, 2026 21:32:21 UTC