What’s Vulnerable › Vulnerabilities
CVE-2026-47674: Hono: IP Restriction bypasses static deny rules for non-canonical IPv6
- Severity: medium (CVSS 5.3 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-05-28 · updated 2026-10-14
- Weakness: CWE-185
Description
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
- honojs hono: before 4.12.21 — fixed in 4.12.21
How to fix
Upgrade to a fixed version: honojs hono 4.12.21. Check the vendor advisory for mitigations.
References
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