Resource exhaustion in Bytecodealliance Wasmtime
CVE-2026-115381
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-gqmc-89g8-p25r (vendor-advisory)
- www.vulncheck.com/advisories/wasmtime-before-36.0.17-37.0.0-before-48.0.4-and-4… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-115381?
- CVE-2026-115381 is a medium-severity vulnerability in Bytecodealliance Wasmtime, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.8/10. Published 2026-10-22.
- How severe is CVE-2026-115381?
- Medium severity. CVSS v3 base score is 4.8 out of 10.