Web Application Framework Vulnerability in Hono
CVE-2026-39409

6.3MEDIUM

Key Information:

Vendor

Honojs

Status
Hono
Vendor
CVE Published:
8 April 2026

What is CVE-2026-39409?

The Hono web application framework has a vulnerability in the ipRestriction() method prior to version 4.12.12. This flaw arises because the function does not appropriately canonicalize IPv4-mapped IPv6 client addresses such as ::ffff:127.0.0.1. As a result, when operating in environments like Node.js with dual-stack configurations, predefined IPv4 allow or deny rules may not apply correctly. This misconfiguration can lead to unintended authorization behavior, potentially allowing unauthorized access. This issue has been resolved in version 4.12.12 of Hono.

Affected Version(s)

hono < 4.12.12

References

https://github.com/honojs/hono/security/advisories/GHSA-x...
x_refsource_CONFIRM
https://github.com/honojs/hono/commit/48fa2233bc092f65011...
x_refsource_MISC
https://github.com/honojs/hono/releases/tag/v4.12.12
x_refsource_MISC

CVSS V4

Score:
6.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.