{"id":"CVE-2026-86076","aliases":["EUVD-2026-74280","GHSA-hw8v-xxg5-vvvx","ROOT-APP-NPM-CVE-2026-86076"],"status":"published","title":"n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution","description":"n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00652,"percentile":0.51699,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":true},"cwes":["CWE-94"],"published":"2026-09-08T21:28:52Z","modified":"2026-10-28T02:30:51Z","exploits":[{"source":"pocgithub","id":"Boreas37/CVE-2026-86076-PoC","title":"Boreas37/CVE-2026-86076-PoC","date":"2026-10-24","url":"https://github.com/Boreas37/CVE-2026-86076-PoC"}],"fixes":[{"ecosystem":"npm","package":"n8n","fixed_in":["1.123.76","2.38.2","2.37.7"],"sources":["ghsa","osv"]},{"ecosystem":"Root:npm","package":"n8n","fixed_in":["2.19.3-aikido.10","2.19.3-aikido.11","2.19.3-aikido.12","2.19.3-aikido.13","2.19.3-aikido.14","2.19.3-aikido.15"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"@rootio/n8n","fixed_in":["2.19.3-root.io.10","2.19.3-root.io.11","2.19.3-root.io.12","2.19.3-root.io.13","2.19.3-root.io.14","2.19.3-root.io.15"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"n8n","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.123.76"}]}]},{"source":"ghsa","ecosystem":"npm","package":"n8n","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.38.0"},{"fixed":"2.38.2"}]}]},{"source":"ghsa","ecosystem":"npm","package":"n8n","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.0.0"},{"fixed":"2.37.7"}]}]},{"source":"osv","ecosystem":"npm","package":"n8n","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.123.76"}]}]},{"source":"osv","ecosystem":"npm","package":"n8n","ranges":[{"type":"SEMVER","events":[{"introduced":"2.38.0"},{"fixed":"2.38.2"}]}]},{"source":"osv","ecosystem":"npm","package":"n8n","ranges":[{"type":"SEMVER","events":[{"introduced":"2.0.0"},{"fixed":"2.37.7"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"n8n","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.19.3-aikido.10"},{"fixed":"2.19.3-aikido.11"},{"fixed":"2.19.3-aikido.12"},{"fixed":"2.19.3-aikido.13"},{"fixed":"2.19.3-aikido.14"},{"fixed":"2.19.3-aikido.15"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"@rootio/n8n","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.19.3-root.io.10"},{"fixed":"2.19.3-root.io.11"},{"fixed":"2.19.3-root.io.12"},{"fixed":"2.19.3-root.io.13"},{"fixed":"2.19.3-root.io.14"},{"fixed":"2.19.3-root.io.15"}]}]}],"products":[{"vendor":"n8n","product":"n8n"},{"vendor":"n8n-io","product":"n8n"}],"references":[{"url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-hw8v-xxg5-vvvx","tags":["x_refsource_CONFIRM","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.76","tags":["x_refsource_MISC","Release Notes","web"]},{"url":"https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7","tags":["x_refsource_MISC","Release Notes","web"]},{"url":"https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2","tags":["x_refsource_MISC","Release Notes","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86076","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-hw8v-xxg5-vvvx"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86076.json","tags":["advisory"]},{"url":"https://github.com/n8n-io/n8n","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-86076","title":"n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution","description":"n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.","status":"published","published":"2026-09-08T21:28:52.762Z","modified":"2026-09-09T15:33:55.77Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T13:49:42.666099Z"}],"euvd":[{"id":"EUVD-2026-74280","description":"n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.","status":"published","published":"2026-09-08T21:28:52Z","modified":"2026-09-09T15:33:55Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T17:28:26.882462Z"}],"ghsa":[{"id":"GHSA-hw8v-xxg5-vvvx","title":"n8n: Expression Sandbox Escape via Class-Field Sanitizer Rebinding Can Lead to Code Execution","description":"## Impact\n\nThe expression compiler's sanitizer resolved through a dynamically-scoped `this`, so a class field named `__sanitize` rebound it and reached the `Function` constructor. On the backend, any expression author could run code in the n8n process; in the editor preview, a member's expression could run as JavaScript in the session of whoever opened the workflow. The patch rejects reserved class-member names.\n\n## Patches\n\nThe issue has been fixed in n8n versions 1.123.76, 2.37.7, and 2.38.2. Users should upgrade to one of these versions or later to remediate the vulnerability.\n\n## Workarounds\n\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Restrict n8n instance access to fully trusted users only.\n- Avoid granting workflow-create or workflow-edit permissions to untrusted users.\n- Audit existing workflows for unexpected or unfamiliar expressions in node parameters.\n- Set `N8N_EXPRESSION_ENGINE=vm`.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.","status":"published","published":"2026-09-10T15:11:07Z","modified":"2026-09-10T15:11:08Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N","level":"high"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T14:41:15.803194Z"}],"nvd":[{"id":"CVE-2026-86076","description":"n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.","status":"published","published":"2026-09-08T22:19:16.387Z","modified":"2026-09-11T18:20:56.68Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T14:12:45.612639Z"}],"osv":[{"id":"CVE-2026-86076","title":"n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution","description":"n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.","status":"published","published":"2026-09-08T21:28:52.762Z","modified":"2026-10-28T02:30:51.083777238Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N","level":"high"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T15:45:18.825071Z"},{"id":"GHSA-hw8v-xxg5-vvvx","title":"n8n: Expression Sandbox Escape via Class-Field Sanitizer Rebinding Can Lead to Code Execution","description":"## Impact\n\nThe expression compiler's sanitizer resolved through a dynamically-scoped `this`, so a class field named `__sanitize` rebound it and reached the `Function` constructor. On the backend, any expression author could run code in the n8n process; in the editor preview, a member's expression could run as JavaScript in the session of whoever opened the workflow. The patch rejects reserved class-member names.\n\n## Patches\n\nThe issue has been fixed in n8n versions 1.123.76, 2.37.7, and 2.38.2. Users should upgrade to one of these versions or later to remediate the vulnerability.\n\n## Workarounds\n\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Restrict n8n instance access to fully trusted users only.\n- Avoid granting workflow-create or workflow-edit permissions to untrusted users.\n- Audit existing workflows for unexpected or unfamiliar expressions in node parameters.\n- Set `N8N_EXPRESSION_ENGINE=vm`.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.","status":"published","published":"2026-09-10T15:11:07Z","modified":"2026-09-10T15:15:05.012966204Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N","level":"high"}],"cwes":["CWE-94"],"updated_at":"2026-11-02T15:46:49.621585Z"},{"id":"ROOT-APP-NPM-CVE-2026-86076","title":"CVE-2026-86076 in n8n - Patched by Root","description":"Root has patched CVE-2026-86076 in the n8n package for Root:npm. Multiple fixed versions available.","status":"published","published":"2026-10-06T03:42:47Z","modified":"2026-10-06T04:15:06.981322769Z","updated_at":"2026-11-02T15:53:27.649662Z"}]}}