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Critical

SandboxJS has a Sandbox Escape

Type: advisorySources: OSV

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, The return values of functions aren't wrapped. Object.values/Object.entries can be used to get an Array containing the host's Function constructor, by using Array.prototype.at you can obtain the hosts Function constructor, which can be used to execute arbitrary code outside of the sandbox. This vulnerability is fixed in 0.8.29.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-25520
Confirmed fixed CVEs
Not specified
Updated in this feed
2 Nov 2026, 20:04 UTC · Revision 1

Source evidence

SandboxJS has a Sandbox Escape

core-osv · Original source

Published 6 Feb 2026, 19:53 UTC

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, The return values of functions aren't wrapped. Object.values/Object.entries can be used to get an Array containing the host's Function constructor, by using Array.prototype.at you can obtain the hosts Function constructor, which can be used to execute arbitrary code outside of the sandbox. This vulnerability is fixed in 0.8.29.

osv:CVE-2026-25520
Complete source record
{
  "id": "647f20a79a19fa7dd98c815a0201a49b3cfb12b96e5e9d6253773424d0a23817",
  "url": "https://osv.dev/vulnerability/CVE-2026-25520",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "SandboxJS has a Sandbox Escape",
    "summary": "SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, The return values of functions aren't wrapped. Object.values/Object.entries can be used to get an Array containing the host's Function constructor, by using Array.prototype.at you can obtain the hosts Function constructor, which can be used to execute arbitrary code outside of the sandbox. This vulnerability is fixed in 0.8.29.",
    "evidence": "osv:CVE-2026-25520",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-25520",
      "aliases": [
        "CVE-2026-25520",
        "GHSA-58jh-xv4v-pcx4"
      ],
      "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-2026-25520.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.276775613Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25520.json",
        "https://github.com/nyariv/SandboxJS/security/advisories/GHSA-58jh-xv4v-pcx4",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-25520",
        "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-2026-25520.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-25520",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489591,
  "published_at": "2026-02-06T19:53:24.219+00:00"
}