CVE-2026-39407 json
Hono has a middleware bypass via repeated slashes in serveStatic
published 7mo ago modified last mo. also EUVD-2026-20493 , GHSA-wmmm-f939-6g9c
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 40%
- public exploits
- 0
- none known
Summary
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.12, a path handling inconsistency in serveStatic allows protected static files to be accessed by using repeated slashes (//) in the request path. When route-based middleware (e.g., /admin/*) is used for authorization, the router may not match paths containing repeated slashes, while serveStatic resolves them as normalized paths. This can lead to a middleware bypass. This vulnerability is fixed in 4.12.12.
Patch / fix
- npm hono 4.12.12
- hono hono 4.12.12
Is CVE-2026-39407 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 7mo ago
Exploit prediction
0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| GitHub | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVD | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | hono | <4.12.12 |
4.12.12 |
Affected products
- honojs hono
Classification
- Weakness
-
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory
References
-
github.com
/honojs/hono/commit/9aff14bd727f8b0435c963363fd803260e7b8e3c
web, patch
-
github.com
/honojs/hono/security/advisories/GHSA-wmmm-f939-6g9c
web, vendor-advisory
-
github.com
/honojs/hono/releases/tag/v4.12.12
web, release-notes
-
nvd.nist.gov
/vuln/detail/CVE-2026-39407
advisory
-
github.com
/honojs/hono
package
Sources
- CVE List CVE-2026-39407
- GitHub Advisory GHSA-wmmm-f939-6g9c
- NVD CVE-2026-39407
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.