CVE 8.3 HIGH

twenty-server SSRF protection bypass via IPv4-mapped IPv6 address normalization_CVE-2026-33975

8.3 / 10
HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N

Description

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.

Basic Information

ID CVE-2026-33975
Source GitHub_M
Published May 5, 2026 at 19:19

Affected Product

Vendor twentyhq
Product twenty
Version <= 1.18.0
Affected Versions twentyhq twenty <= 1.18.0

CWE Classification

References

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