CVE-2026-47674: Hono

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, the ip-restriction middleware (hono/ip-restriction) compares incoming IP addresses against configured deny and allow rules using string equality after partial normalization. Non-canonical IPv6 representations of an address already listed in a static rule — such as compressed forms, explicit-zero forms, or hex-notation IPv4-mapped addresses — do not match the normalized rule entry, causing the rule to be silently skipped. This vulnerability is fixed in 4.12.21.

Affected products

• Hono Hono: before 4.12.21 (fixed in 4.12.21)

Published 2026-05-28. Last modified 2026-06-17.