VulnerabilityAnalyzed

CVE-2026-39408

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.

MEDIUM 5.9EPSS 0.53%

Does this matter?

Lower severity and a low EPSS score (0.53%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 5.9 MEDIUMCVSS: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/M
EPSS: 0.53% probability · 43th percentile
CISA KEV: Not listed
Weakness: CWE-22
Affected: hono/hono
Source: security-advisories@github.com

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

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.