Description
Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
References2
Metrics
- CVSS 3.1
-
2.3
LOW
Score source: CNA
CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L - CVSS 4.0
-
1.0
LOW
Score source: CNA
CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 4 · as of 8 November 2026
- CWE
- CWE-770
Could this be exploited in your environment?
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