CVE-2026-29045
criticalpriority · track · 39EPSS 0.005 · 45 %ileDEEUUSEPSS · scored 2026-10-27
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to version 4.12.4, when using serveStatic together with route-based middleware protections (e.g. app.use('/admin/*', ...)), inconsistent URL decoding allowed protected static resources to be accessed without authorization. The router used decodeURI, while serveStatic used decodeURIComponent. This mismatch allowed paths containing encoded slashes (%2F) to bypass middleware protections while still resolving to the intended filesystem path. This issue has been patched in version 4.12.4.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8
ssvc
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weaknesses
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affected products (11)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-0933IBM App Connect Enterprise (Hono und Undici): Mehrere SchwachstellenDeutsch2026-03-30csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in IBM App Connect Enterprise ausnutzen, um Sicherheitsvorkehrungen zu umgehen, Daten zu manipulieren, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand herbeizuführen oder andere nicht näher bezeichnete Angriffe durchzuführen.
- GHSA-q5qw-h33p-qvwrHono vulnerable to arbitrary file access via serveStatic vulnerability 2026-03-04ghsa · osvUS
## Summary When using `serveStatic` together with route-based middleware protections (e.g. `app.use('/admin/*', ...)`), inconsistent URL decoding allowed protected static resources to be accessed without authorization. The router used `decodeURI`, while `serveStatic` used `decodeURIComponent`. This mismatch allowed paths containing encoded slashes (`%2F`) to bypass middleware protections while still resolving to the intended filesystem path. ## Details The routing layer preserved `%2F` as a literal string, while `serveStatic` decoded it into `/` before resolving the file path. Example: Request: `/admin%2Fsecret.html` - Router sees: `/admin%2Fsecret.html` → does not match `/admin/*` - Static handler resolves: `/admin/secret.html` As a result, static files under the configured static root could be served without triggering route-based protections. This only affects applications that both: - Protect subpaths using route-based middleware, and - Serve files from the same static root using `serveStatic`. This does **not** allow access outside the static root and is **not** a path traversal vulnerability. ## Impact An unauthenticated attacker could bypass route-based authorization for protected static resources by supplying paths containing encoded slashes. Applications relying solely on route-based middleware to protect static subpaths may have exposed those resources.
also known as (3)
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sources
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references (7)
External citations — patches, advisories, analysis.
- https://github.com/honojs/hono/commit/6a0607a929d888893f0c91d92dce2fcfdb3662a3cnnvd
- https://github.com/honojs/hono/releasesPatchcnnvd
- https://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwrcnnvd
- https://github.com/honojs/hono/commit/6a0607a929d888893f0c91d92dce2fcfdb3662a3enisa_euvd
- https://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwrenisa_euvd
- https://github.com/honojs/hono/commit/6a0607a929d888893f0c91d92dce2fcfdb3662a3Patchnvd
- https://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwrVendor Advisorynvd
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