https://cybercrime.club/tags/webhook/Recent content in Webhook on cybercrime.clubHugoen-usSat, 04 Apr 2026 14:08:56 -0400https://cybercrime.club/posts/n8n-cve-2026-21858-ni8mare-unauthenticated-rce/Sat, 04 Apr 2026 14:08:56 -0400https://cybercrime.club/posts/n8n-cve-2026-21858-ni8mare-unauthenticated-rce/<p>A maximum-severity (CVSS 10.0) unauthenticated remote code execution vulnerability in n8n — one of the most widely deployed open-source workflow automation platforms — has a public proof-of-concept and is being actively tracked. If you&rsquo;re running an internet-accessible n8n instance, this warrants immediate action.</p> <h2 id="what-happened">What Happened</h2> <p>Cyera Research Labs discovered and responsibly disclosed <strong>CVE-2026-21858</strong>, dubbed &ldquo;Ni8mare,&rdquo; a content-type confusion bug in n8n&rsquo;s webhook and file-upload handling logic. The flaw allows a completely unauthenticated attacker to read arbitrary files from the underlying host, steal internal credentials, forge administrator sessions, and ultimately execute arbitrary code on the server.</p>