CVE-2026-115389
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.
Does this matter?
Lower severity and a low EPSS score (0.15%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 1.0 LOWCVSS: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/M
- EPSS
- 0.15% probability · 4th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Source
- disclosure@vulncheck.com
EPSS moved from 0.2% on 23 October 2026 to 0.2% on 27 October 2026.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.