Hono has a path traversal in toSSG() allows writing files outside the output directory

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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.

Source published

8 Apr 2026 14:42:25 UTC

Source modified

10 Apr 2026 20:31:47 UTC

Saved here

23 Oct 2026 15:48:27 UTC

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CVE Program Terms of Use

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CVSS 4.0 · 5.9 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

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.

Source published

Apr 8, 2026, 2:42:25 PM (timezone not stated)

Source modified

Apr 10, 2026, 8:31:47 PM (timezone not stated)

Saved here

15 Nov 2026 11:06:13 UTC

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ENISA EUVD · source terms and attribution apply

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Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

EUVD CVSS 4.0 · 5.9 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

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.

Source published

8 Apr 2026 15:16:14 UTC

Source modified

24 Jul 2026 21:10:00 UTC

Saved here

25 Oct 2026 09:17:18 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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CVSS 4.0 · [email protected] · Secondary · 5.9 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

CVSS 3.1 · [email protected] · Primary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS 3.1 · 134c704f-9b21-4f2e-91b3-4a467353bcc0 · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

## Summary 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. ## Details The static site generation process creates output files based on route paths derived from application routes and parameters. When `ssgParams` is used to provide values for dynamic routes, those values are used to construct output file paths. If these values contain traversal sequences (e.g. `..`), the resulting output path may resolve outside the configured output directory. As a result, files may be written to unintended locations instead of being confined within the specified output directory. For example: ```ts import { Hono } from 'hono' import { toSSG, ssgParams } from 'hono/ssg' const app = new Hono() app.get('/:id', ssgParams([{ id: '../pwned' }]), (c) => { return c.text('pwned') }) toSSG(app, fs, { dir: './static' }) ``` In this case, the generated output path may resolve outside `./static`, resulting in a file being written outside the intended output directory. ## Impact An attacker who can influence values passed to `ssgParams` during the build process may be able to write files outside the intended output directory. Depending on the build and deployment environment, this may: * overwrite unintended files * affect generated artifacts * impact deployment outputs or downstream tooling This issue is limited to build-time static site generation and does not affect request-time routing.

Source published

8 Apr 2026 00:16:51 UTC

Source modified

10 Sep 2026 03:51:03 UTC

Saved here

24 Oct 2026 13:17:17 UTC

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GitHub Advisory Database · CC-BY-4.0

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CVSS_V4 · 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

Publisher rating · MODERATE