Vulnerability Description
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.12, ipRestriction() does not canonicalize IPv4-mapped IPv6 client addresses (e.g. ::ffff:127.0.0.1) before applying IPv4 allow or deny rules. In environments such as Node.js dual-stack, this can cause IPv4 rules to fail to match, leading to unintended authorization behavior. This vulnerability is fixed in 4.12.12.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Hono | Hono | <= 4.12.11 |
Related Weaknesses (CWE)
References
- https://github.com/honojs/hono/commit/48fa2233bc092f650119f42df043050737cabf39Patch
- https://github.com/honojs/hono/releases/tag/v4.12.12Release Notes
- https://github.com/honojs/hono/security/advisories/GHSA-xpcf-pg52-r92gVendor Advisory
FAQ
What is CVE-2026-39409?
CVE-2026-39409 is a vulnerability with a CVSS score of 5.3 (MEDIUM). Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.12, ipRestriction() does not canonicalize IPv4-mapped IPv6 client addresses (e.g. ::ffff:127.0.0.1) ...
How severe is CVE-2026-39409?
CVE-2026-39409 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-39409?
Check the references section above for vendor advisories and patch information. Affected products include: Hono Hono.