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

{
  "id": "fa3e19da1736f5481d86b3508e1eeffa0cf4d6d0baf54b0f3319797b38163be6",
  "url": "https://osv.dev/vulnerability/CVE-2026-115389",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "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 WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.",
    "evidence": "osv:CVE-2026-115389",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-115389",
      "aliases": [
        "CVE-2026-115389",
        "GHSA-jqpg-j7w6-42pr",
        "RUSTSEC-2026-0316"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/bytecodealliance/wasmtime",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "5cd4bf51aad8ae193823d35a05bfa97dd8dc3f11"
                },
                {
                  "introduced": "7b3d6ae79e9153a2477668062f5622c10333925f"
                },
                {
                  "fixed": "ebf20ab7cbf35fa3fbd8202562017fda6a541021"
                },
                {
                  "introduced": "17830bd3c0331d920a8aa38846eebc4d46d98c23"
                },
                {
                  "fixed": "46c23a87dac1465986a8ad53ba6a7ae49372857b"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "36.0.16"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "37.0.0"
                      },
                      {
                        "fixed": "48.0.3"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "49.0.0"
                      },
                      {
                        "fixed": "49.0.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v49.0.0",
            "v48.0.2",
            "v36.0.15",
            "v48.0.1",
            "v36.0.14",
            "v48.0.0",
            "v36.0.13",
            "v36.0.12",
            "v36.0.11",
            "v36.0.10",
            "v36.0.9",
            "v36.0.8",
            "v36.0.7",
            "v36.0.6",
            "v36.0.5",
            "dev",
            "v36.0.4",
            "v36.0.3",
            "v36.0.2",
            "v36.0.1",
            "v36.0.0",
            "v0.35.0",
            "v0.33.0",
            "v0.34.0",
            "v0.32.0",
            "v0.31.0",
            "v0.30.0",
            "v0.29.0",
            "v0.28.0",
            "v0.27.0",
            "v0.26.0",
            "v0.25.0",
            "v0.24.0",
            "v0.23.0",
            "v0.22.0",
            "cranelift-v0.69.0",
            "v0.21.0",
            "v0.20.0",
            "v0.19.0",
            "v0.18.0",
            "v0.17.0",
            "v0.16.0",
            "cranelift-v0.61.0",
            "cranelift-v0.60.0",
            "v0.12.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-115389.json"
          }
        }
      ],
      "modified": "2026-10-31T02:30:38.740117791Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/115xxx/CVE-2026-115389.json",
        "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-jqpg-j7w6-42pr",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-115389",
        "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"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-770"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/115xxx/CVE-2026-115389.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-115389",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 505350,
  "published_at": "2026-10-22T19:13:55.163+00:00"
}