{"id":"CVE-2026-115389","title":"Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API","summary":"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 WebA…","severity":"low","cvss":2.3,"cvssVector":"CVSS:3.1/AV:A/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L","cvssSource":"cna","cwe":["CWE-770"],"vendor":"bytecodealliance","product":"wasmtime","affected":["wasmtime < 36.0.16","wasmtime >= 37.0.0 < 48.0.3","wasmtime >= 49.0.0 < 49.0.1"],"published":"2026-10-22","updated":"2026-10-22","sourceUpdated":"2026-10-22T19:13:55.163Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-115389","references":[{"url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-jqpg-j7w6-42pr","label":"GitHub Security Advisory (GHSA-jqpg-j7w6-42pr)"},{"url":"https://www.vulncheck.com/advisories/wasmtime-before-36.0.16-37.0.0-before-48.0.3-and-49.0.0-before-49.0.1-denial-of-service-via-val-api","label":"VulnCheck Advisory: Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API"}],"tags":["cve.org"],"ingestedAt":"2026-10-22T22:00:50.405Z","slug":"CVE-2026-115389","body":"## Overview\n\nWasmtime 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.\n\n## Affected\n\n- `wasmtime < 36.0.16`\n- `wasmtime >= 37.0.0 < 48.0.3`\n- `wasmtime >= 49.0.0 < 49.0.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":13,"depthScoreParts":{"impact":12.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}