CVE-2026-84365Hono: Incomplete fix for CVE-2026-39408: `toSSG()` still writes files outside the output directory
Updated under an hour ago ()
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Hono is a Web application framework that provides support for any JavaScript runtime. From 4.12.12 until 4.13.5, the fix released for CVE-2026-39408 does not cover every traversal sequence, and toSSG() can still write files outside the configured output directory when a route parameter contains consecutive parent-directory segments. Static site generation builds each output path from the route path and values supplied through ssgParams, then verifies that the result stays inside the output directory using the same normalization routine that built the path. That routine does not fully collapse runs of consecutive parent-directory segments, allowing a path that the check accepts to resolve outside the output directory, and the check also treats output directories that differ in how they are rooted as equivalent. This arises when an application generates a static site from route parameter values it does not fully control, such as slugs from a CMS, API, or user submission. An untrusted ssgParams value can create or overwrite files elsewhere in the build environment and alter generated artifacts or deployment output. The vulnerability affects build-time static site generation only; request-time routing and applications with entirely developer-controlled ssgParams values are not affected. This issue is fixed in version 4.13.5.
- CVSS
- 6.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
- Weakness (CWE)
- CWE-22
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Deferred
- Record last updated
- Sep 4, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
honojs hono honojs:hono (from the name) | before 4.13.5 | CNA record |
References
- https://github.com/honojs/hono/security/advisories/GHSA-gqvv-2mrq-wpjvx-refsource-confirm
- https://github.com/honojs/hono/commit/3a67f7f3997e1437d108f7bcba2dbcee2df69221x-refsource-misc
- https://github.com/honojs/hono/releases/tag/v4.13.5x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.