CVE-2026-101910

Name of the Vulnerable Software and Affected Versions ip-address versions 10.2.0 through 10.5.0

Description The Address6.isPrivate classifier in src/ipv6.ts fails to recognize the NAT64 local-use range 64:ff9b:1::/48. Consequently, the isPrivate(), isLoopback(), and isLinkLocal() functions return false for addresses within this range, causing internal IPv4 destinations encoded via a local-use NAT64 prefix to be incorrectly identified as global addresses. This can lead to a trust-boundary bypass in applications using these checks to prevent Server-Side Request Forgery (SSRF), an attack where a user-supplied address tricks a server into making requests to internal destinations, such as loopback services or cloud metadata endpoints. Exploitation requires the server network to use an operator-selected NAT64 prefix within the local-use range.

Recommendations Update ip-address to version 10.5.1. As a temporary workaround, manually test if a host is within the NAT64 local-use range by using isHostInSubnet() with the 64:ff9b:1::/48 subnet.