CVE-2026-39408

highpriority · track · 30EPSS 0.004 · 38 %ileDEEUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.45% (38th) EPSS
CVSS 7.5 · high
Is it mine?
27 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · cert_bund · osv

EPSS · scored 2026-10-22

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

7.5
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–high · 2.1–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 3.6
v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondaryexploitability 3.9 · impact 3.6
v4.05.9mediumCVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:Nsecondary · ENISA EU
v4.05.9mediumCVSS: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:Xsecondary · security-advisories@github.com
v4.02.1lowCVSS: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:U/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:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (27)

Products and version ranges known to be affected.

showing 20 of 27
05

advisories (2)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-1407IBM App Connect Enterprise Certified Container: Mehrere SchwachstellenDeutsch2026-05-06csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen in IBM App Connect Enterprise Certified Container ausnutzen, um beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, Cross-Site-Scripting-Angriffe durchzuführen, Daten zu manipulieren, vertrauliche Informationen offenzulegen oder einen Denial-of-Service-Zustand zu verursachen.

  • GHSA-xf4j-xp2r-rqqxHono: Path traversal in toSSG() allows writing files outside the output directory2026-04-08ghsa · osvUS

    ## 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.

06

also known as (3)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

published 2026-04-08modified 2026-07-24
08

references (11)

External citations — patches, advisories, analysis.

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