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.

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. Whe…

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.005 (41.4th percentile) — read the EPSS interpretation.

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.

Affected products

Hono
Honojs Hono — versions < 4.12.12

Weakness classification (CWE)

CWE-22 — Path Traversal

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC, 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.