Hono: Arbitrary file access via serveStatic vulnerability
cve-program · CVE-2026-29045
PublishedHono 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.
Read the publisher's advisoryeuvd · EUVD-2026-9506
PublishedHono 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.
Read the publisher's advisorynvd · CVE-2026-29045
PublishedHono 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.
Read the publisher's advisoryosv · GHSA-q5qw-h33p-qvwr
Published## 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.
Read the publisher's advisoryAffected versions, risk and source history
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cve-program · CVE-2026-29045
PublishedHono: Arbitrary file access via serveStatic vulnerability
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.
- Source published
- 4 Mar 2026 22:09:22 UTC
- Source modified
- 5 Mar 2026 15:42:05 UTC
- Saved here
- 23 Oct 2026 15:48:27 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
euvd · EUVD-2026-9506
PublishedHono 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 decodin…
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.
Additional publisher context
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Mar 4, 2026, 10:09:22 PM
dateUpdated: Mar 5, 2026, 3:42:05 PM
1 related source bulletins · separate from aliases
WID-SEC-W-2026-0933: IBM App Connect Enterprise (Hono und Undici): Mehrere Schwachstellen
CVE-2026-1525 · CVE-2026-1526 · CVE-2026-1528 · CVE-2026-2229 · CVE-2026-2581 · CVE-2026-29045 · CVE-2026-29085 · CVE-2026-29086 · CVE-2026-1527
- Source published
- Mar 4, 2026, 10:09:22 PM (timezone not stated)
- Source modified
- Mar 5, 2026, 3:42:05 PM (timezone not stated)
- Saved here
- 15 Nov 2026 12:01:17 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
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 3.1 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd · CVE-2026-29045
PublishedHono 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 decodin…
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.
Additional publisher context
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Analyzed
Weakness classifications: CWE-177
Original publisher date fields
published: 2026-03-04T23:16:10.247
lastModified: 2026-06-17T10:29:30.013
1 source CPE criteria · context only
- cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
- Source published
- 4 Mar 2026 23:16:10 UTC
- Source modified
- 17 Jun 2026 10:29:30 UTC
- Saved here
- 25 Oct 2026 07:19:03 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · [email protected] · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS 3.1 · [email protected] · Primary · 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
osv · GHSA-q5qw-h33p-qvwr
PublishedHono vulnerable to arbitrary file access via serveStatic vulnerability
## 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.
- Source published
- 4 Mar 2026 19:48:00 UTC
- Source modified
- 10 Sep 2026 03:50:40 UTC
- Saved here
- 24 Oct 2026 13:17:17 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
Source: osv · GitHub Advisory Database · CC-BY-4.0. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Publisher rating · HIGH