CVE-2026-39408 MEDIUM

CVE-2026-39408: Hono has a path traversal in toSSG() allows writing files outside the output directory

Vendor Honojs
Product hono
Weakness CWE-22 · Path traversal
Published April 8, 2026
Last update April 10, 2026
View on NVD All CVEs

CVSS base score

5.9/10
Attack vector Local
Attack complexity High
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS vector

CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.12, a path traversal issue in toSSG() allows files to be written outside the configured output directory during static site generation. When using dynamic route parameters via ssgParams, specially crafted values can cause generated file paths to escape the intended output directory. This vulnerability is fixed in 4.12.12.

Key dates

02Disclosure timeline

April 8, 2026 CVE published
April 10, 2026 Record updated