n8n has patched a high-severity expression-sandbox escape vulnerability that allows authenticated workflow editors to execute operating-system commands on the server running the automation platform. Security Joes discovered the flaw while analyzing n8n’s February fix for CVE-2026-27577, a critical sandbox escape. The new vulnerability, assigned CVE-2026-XXXX (pending), affects n8n versions 2.32.0 to 2.31.4. The exploit leverages two blind spots: an unhandled arrow function expression in the identifier-rewriting layer, which allows bare identifiers like ‘process’ to resolve to the real Node.js global, and a gap in property checks that lets Reflect.get() bypass static property name inspections. Researchers used these to recover process.getBuiltinModule, load child_process, and execute commands on the host. The proof-of-concept was tested against n8n 2.30.4. n8n published fixed releases on July 22, 2026. Defenders should review workflows for unexpected arrow functions or obfuscated JavaScript, monitor for suspicious child processes (shells, PowerShell, curl, wget), and rotate credentials if compromise is suspected. This finding continues a series of sandbox escapes patched by n8n since 2025.
CVEs: CVE-2026-27577, CVE-2026-50522
Companies: n8n, Security Joes
Products: n8n
Original source: thehackernews.com