CVE-2026-33975 — twenty-server SSRF protection bypass via IPv4-mapped IPv6 address normalization
Twenty is an open source CRM built with NestJS (Node.js). In versions 1.18.0 and earlier, the SSRF protection in twenty-server's SecureHttpClientService can be bypassed using IP…
Published: 2026-05-05 · CVSS: 8.3 · CVSS 4.0
Twenty is an open source CRM built with NestJS (Node.js). In versions 1.18.0 and earlier, the SSRF protection in twenty-server's SecureHttpClientService can be bypassed using IPv4-mapped IPv6 addresses in URL IP literals. Node.js's URL parser normalizes IPv4-mapped IPv6 addresses to compressed hex form (e.g., ::ffff:169.254.169.254 becomes ::ffff:a9fe:a9fe), but the isPrivateIp utility only recognizes the dotted-decimal notation. As a result, the hex form passes the SSRF check unchecked. Additionally, the socket lookup validation event does not fire for IP literal addresses, bypassing the second validation layer. An authenticated user can reach any internal IP, including cloud metadata endpoints, to exfiltrate credentials such as IAM keys.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7