Resource exhaustion in Bytecodealliance Wasmtime
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. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 2.3 (Low). Vector: CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L.
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-jqpg-j7w6-42pr (vendor-advisory)
- www.vulncheck.com/advisories/wasmtime-before-36.0.16-37.0.0-before-48.0.3-and-4… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-115389?
- CVE-2026-115389 is a low-severity vulnerability in Bytecodealliance Wasmtime, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 2.3/10. Published 2026-10-22.
- How severe is CVE-2026-115389?
- Low severity. CVSS v3 base score is 2.3 out of 10.