CVE-2026-101913: Beaugunderson IP-Address

Medium severity, CVSS 6.3. EPSS: 0.4% chance of exploitation in the next 30 days.

ip-address is a library for parsing and manipulating IPv4 and IPv6 addresses in JavaScript. Prior to 10.5.1, the Address6 isLinkLocal method in src/ipv6.ts recognizes only fe80::/64 instead of the complete fe80::/10 IPv6 link-local range. An attacker-controlled address elsewhere in fe80::/10 can therefore pass a trust-boundary check that relies on isLinkLocal. The same address is identified as link-local by getType and getScope, exposing the inconsistent classification. A successful bypass can reach an on-link host outside the intended trust boundary. This issue is fixed in version 10.5.1.

Affected products

• Beaugunderson IP-Address: before 10.5.1 (fixed in 10.5.1)

Published 2026-09-28. Last modified 2026-09-30.