Path Traversal in Hono
CVE-2026-39408
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (36.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.004 · change: -0.001
Affected products
- Hono
- Honojs Hono — versions < 4.12.12
Weakness classification (CWE)
References
- github.com/honojs/hono/security/advisories/GHSA-xf4j-xp2r-rqqx (Exploit, Vendor Advisory)
- github.com/honojs/hono/commit/b470278920fffcfd6d76002755d6db53db827679 (Patch)
- github.com/honojs/hono/releases/tag/v4.12.12 (Release Notes)
Frequently asked questions
- What is CVE-2026-39408?
- CVE-2026-39408 is a high-severity vulnerability in Hono, classified under Path Traversal. CVSS score: 7.5/10. Published 2026-04-08.
- How severe is CVE-2026-39408?
- High severity. CVSS v3 base score is 7.5 out of 10.