SandboxJS has a Sandbox Escape via Prototype Whitelist Bypass and Host Prototype Pollution

{
  "id": "ef89d9c61892e235fe9f117a45597c1aa9798579c1b9c826f21eb4c4c985ac0b",
  "url": "https://osv.dev/vulnerability/CVE-2026-25586",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "SandboxJS has a Sandbox Escape via Prototype Whitelist Bypass and Host Prototype Pollution",
    "summary": "SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, a sandbox escape is possible by shadowing hasOwnProperty on a sandbox object, which disables prototype whitelist enforcement in the property-access path. This permits direct access to __proto__ and other blocked prototype properties, enabling host Object.prototype pollution and persistent cross-sandbox impact. This vulnerability is fixed in 0.8.29.",
    "evidence": "osv:CVE-2026-25586",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-25586",
      "aliases": [
        "CVE-2026-25586",
        "GHSA-jjpw-65fv-8g48"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/nyariv/sandboxjs",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "67cb186c41c78c51464f70405504e8ef0a6e43c3"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.8.29"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "67cb186c41c78c51464f70405504e8ef0a6e43c3"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "cpe": "cpe:2.3:a:nyariv:sandboxjs:*:*:*:*:*:node.js:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.8.29"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.8.28",
            "0.8.24-2",
            "0.8.24-1",
            "0.8.24",
            "0.8.23.3",
            "0.8.23-1",
            "0.8.23.2",
            "0.8.23",
            "0.8.22",
            "0.8.21",
            "0.8.20",
            "0.8.19",
            "0.8.18",
            "0.8.17",
            "0.8.16",
            "0.8.15.1",
            "0.8.15",
            "0.8.14",
            "0.8.12",
            "0.8.11",
            "0.8.10",
            "0.8.9",
            "0.8.8",
            "0.8.7",
            "0.8.6",
            "0.8.5",
            "0.8.4",
            "0.8.3",
            "0.8.2",
            "0.8.0",
            "0.7.1",
            "0.7.0",
            "0.6.2",
            "0.6.1",
            "0.6.0",
            "0.5.3",
            "0.5.2",
            "0.5.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25586.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.383269917Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25586.json",
        "https://github.com/nyariv/SandboxJS/security/advisories/GHSA-jjpw-65fv-8g48",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-25586",
        "https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-74"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25586.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-25586",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489592,
  "published_at": "2026-02-06T19:54:38.446+00:00"
}