CVE-2026-101910

ip-address: no classifier recognizes the NAT64 local-use range 64:ff9b:1::/48, allowing SSRF and trust-boundary bypass

MEDIUM
6.9
CVSS Score
Published: September 28, 2026 at 05:45 PM UTC
Updated: September 30, 2026 at 07:57 PM UTC
1 product affected across 1 vendorIP Address

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Severity
MEDIUM6.9
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

ip-address is a library for parsing and manipulating IPv4 and IPv6 addresses in JavaScript. From 10.2.0 until 10.5.1, the Address6 isPrivate classifier in src/ipv6.ts does not recognize the NAT64 local-use range 64:ff9b:1::/48. Applications that combine isPrivate, isLoopback, and isLinkLocal for a trust-boundary decision can treat an internal IPv4 destination encoded through that range as external. Exploitation depends on a server network using an operator-selected NAT64 prefix within the local-use range. A successful bypass can cross the intended network trust boundary. This issue is fixed in version 10.5.1.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 10.5.1
Affected range stops below 10.5.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.9MEDIUMGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-918

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