Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an unbounded memory allocation in the wasmtime-wasi WASIp2 write-zeroes method of SinkOutputStream, the default stream used when stdout/stderr are not configured. A malicious WebAssembly guest can request huge zero-filled writes, exhausting host memory and causing denial of service.
https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-gqmc-89g8-p25r
Published: 2026-10-22
Updated: 2026-10-22
Base Score: 4.9
Vector: CVSS2#AV:N/AC:H/Au:S/C:N/I:N/A:C
Severity: Medium
Base Score: 4.8
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H
Severity: Medium
Base Score: 5.9
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: Medium