ip-address JS 10.1.1-10.2.1 IP Classifier Mask Bypass
CVE-2026-69198 Published on August 3, 2026
ip-address: a CIDR suffix on the parsed address suppresses special-use classification and can bypass SSRF and trust-boundary checks
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.
Vulnerability Analysis
CVE-2026-69198 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. Public availability of a proof of concept (POC) exploit exists for CVE-2026-69198. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Types
Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
What is a SSRF Vulnerability?
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. By providing URLs to unexpected hosts or ports, attackers can make it appear that the server is sending the request, possibly bypassing access controls such as firewalls that prevent the attackers from accessing the URLs directly. The server can be used as a proxy to conduct port scanning of hosts in internal networks, use other URLs such as that can access documents on the system (using file://), or use other protocols such as gopher:// or tftp://, which may provide greater control over the contents of requests.
CVE-2026-69198 has been classified to as a SSRF vulnerability or weakness.