CVE-2026-39408

Name: CVE-2026-39408
Creator: NVD / NIST
Published: 2026-04-08T15:16:14.823+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.9/10EPSS 0.53%

Last modified Jun 17, 2026

CVE-2026-39408 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. 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. EPSS estimates a 0.53% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS 4.0

5.9/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.53%

40.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-22

Affected Software

Vendor	Product	Versions
Hono	Hono	>= 4.0.0, <= 4.12.11

References

https://github.com/honojs/hono/commit/b470278920fffcfd6d76002755d6db53db827679Patch
https://github.com/honojs/hono/releases/tag/v4.12.12Release Notes
https://github.com/honojs/hono/security/advisories/GHSA-xf4j-xp2r-rqqxExploit, Vendor Advisory

Timeline

Published: Apr 8, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-39408?

How severe is CVE-2026-39408?

CVE-2026-39408 has a CVSS score of 5.9/10 (MEDIUM severity). The EPSS model estimates a 0.53% probability of exploitation in the next 30 days.

How do I fix CVE-2026-39408?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-39408?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST