ip-address is a library for parsing and manipulating IPv4 and IPv6 addresses in JavaScript. From 10.1.1 until 10.2.2, every special-use classification method is built on isInSubnet, which short-circuits to false whenever the address's own subnet mask is shorter than the reference range's mask. That mask comes verbatim from the CIDR suffix on the parsed input, so appending a suffix such as /0 suppresses classification entirely: isLoopback(), isPrivate(), isLinkLocal(), isCGNAT(), isMulticast(), isUnspecified(), isBroadcast(), isULA(), and getType() all report an internal address as unremarkable, while correctForm() and address still return the real internal target. An application that builds a network trust-boundary decision on these checks, for example a filter intended to block Server-Side Request Forgery, or SSRF, may therefore treat an internal target as external and allow the request. The underlying bit comparison is correct, and mask(n) already returns the first n bits of the full parsed address independently of subnetMask; the defect is solely that the containment guard sits in the classification path. This issue is fixed in version 10.2.2.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 1
- First seenCVSS 6.9NVD modified 2026-10-23 21:10
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 4
- https://github.com/beaugunderson/ip-address/commit/488fe9bc7c35363b4b090494fc38c266d217740d
- https://github.com/beaugunderson/ip-address/releases/tag/v10.2.2
- https://github.com/beaugunderson/ip-address/security/advisories/GHSA-4xrf-jv44-h6hh
- https://github.com/beaugunderson/ip-address/security/advisories/GHSA-4xrf-jv44-h6hh