Incorrect Behavior Order: Validate Before Canonicalize Affecting hono package, versions <4.12.12
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-HONO-15928834
- published8 Apr 2026
- disclosed8 Apr 2026
- creditr74tech
Introduced: 8 Apr 2026
CVE-2026-39409 (opens in a new tab)How to fix?
Upgrade hono to version 4.12.12 or higher.
Overview
hono is an Ultrafast web framework for the Edges
Affected versions of this package are vulnerable to Incorrect Behavior Order: Validate Before Canonicalize in the ipRestriction function. An attacker can bypass access restrictions by sending requests from IPv4-mapped IPv6 addresses, which are not properly matched against IPv4 allow or deny rules.