CVE-2026-47674

Hono: IP Restriction bypasses static deny rules for non-canonical IPv6

MEDIUM
5.3
CVSS Score
Published: May 28, 2026 at 03:29 PM UTC
Updated: October 14, 2026 at 08:10 PM UTC
2 products affected across 2 vendorsHonoHono

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.12.21
v < 4.12.21
Affected range stops below 4.12.21, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/honojs/hono/security/advisories/GHSA-xrhx-7g5j-rcj5

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-185CWE-1289

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