Wasmtime with Winch compiler backend may allow a sandbox-escaping memory access

{
  "id": "05456e578b6c1e522b634e6cf880abc71676b33e2d66b01b0d784dcdd2b88f0e",
  "url": "https://osv.dev/vulnerability/RUSTSEC-2026-0095",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Wasmtime with Winch compiler backend may allow a sandbox-escaping memory access",
    "summary": "This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-xx5w-cvp6-jv83 For more information see the GitHub-hosted security advisory.",
    "evidence": "osv:RUSTSEC-2026-0095",
    "products": [
      {
        "name": {
          "value": "wasmtime",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "36.0.7",
            "evidence": "/affected/0/ranges"
          },
          {
            "value": "42.0.2",
            "evidence": "/affected/0/ranges"
          },
          {
            "value": "43.0.1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "RUSTSEC-2026-0095",
      "aliases": [
        "CVE-2026-34987",
        "GHSA-xx5w-cvp6-jv83",
        "RUSTSEC-2026-0095"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0.0.0-0"
                },
                {
                  "fixed": "36.0.7"
                },
                {
                  "introduced": "37.0.0"
                },
                {
                  "fixed": "42.0.2"
                },
                {
                  "introduced": "43.0.0"
                },
                {
                  "fixed": "43.0.1"
                }
              ]
            }
          ],
          "package": {
            "name": "wasmtime",
            "purl": "pkg:cargo/wasmtime",
            "ecosystem": "crates.io"
          },
          "database_specific": {
            "cvss": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
            "source": "https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0095.json",
            "categories": [],
            "informational": null
          },
          "ecosystem_specific": {
            "affects": {
              "os": [],
              "arch": [],
              "functions": []
            },
            "affected_functions": null
          }
        }
      ],
      "modified": "2026-10-12T18:00:08.330233116Z",
      "provider": "osv",
      "references": [
        "https://crates.io/crates/wasmtime",
        "https://rustsec.org/advisories/RUSTSEC-2026-0095.html",
        "https://github.com/bytecodealliance/wasmtime/pull/13014"
      ],
      "provider_metadata": {
        "license": "CC0-1.0"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-34987",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 306384,
  "published_at": "2026-04-09T12:00:00+00:00"
}