VulnerabilityDeferred

CVE-2026-33975

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.

HIGH 8.3EPSS 0.24%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 8.3 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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/M
EPSS: 0.24% probability · 15th percentile
CISA KEV: Not listed
Weakness: CWE-918
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.