5.3 Medium

@hono/node-server: `serveStatic` decodes the request path a second time, leading to bypass of middleware on static paths

CVE-2026-118663

Summary serveStatic decodes the request path a second time after Hono has already decoded it for routing. A crafted request can be routed as one path and served as another, so middleware mounted on a static prefix does not run for a file under that prefix. Details Hono decodes the request path once before routing. serveStatic decoded it again before resolving the file. With a malformed percent-encoded sequence, the first decode leaves part of the path encoded, the router matches the encoded form, and the second decode resolves the real directory. The file is still resolved inside the configured root; this is not a traversal outside it. Impact An unauthenticated attacker may reach static files without the middleware on their prefix running, for example an authentication check. This affects applications that mount middleware on part of the directory served by serveStatic. Applications that serve only public files are not affected.

Assessment

CVSS: 5.3 (v3.1)
Severity: Medium
EPSS: 0.00353% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 28 October 2026
Last updated: 28 October 2026
Affected: npm · @hono/node-server
Weakness: CWE-174

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

At the source

GitHub Advisories

References

Community proofs of concept

No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.

Submit a proof of concept

Only for publicly disclosed vulnerabilities, and only material from testing you were authorised to perform. This platform does not buy, sell, or broker exploits — see earning from vulnerability research for legitimate bounty programs. Submissions are reviewed before they appear. Text only; do not include live credentials, personal data, or anything targeting systems you are not permitted to test.

Title *

Proof of concept *

Write-up (optional)

Affected versions (optional)

Name or handle (optional)

References (optional, one URL per line)

Licence for your contribution *

Private contact (optional, never shown)

Before you submit * This vulnerability is already publicly disclosed (it has a published CVE). This material comes only from testing I was authorised to perform. I have the legal right to publish this content and am not breaching any agreement by doing so. It contains no live credentials, personal data, or anything targeting systems I am not authorised to test. I understand it will be reviewed before it appears publicly and may be rejected. I agree to the submission terms.

What is 5 + 4? *

Query this programmatically

Agents can read this through the MCP endpoint, or over HTTP:

curl https://cve.zerocrew.in/api/cve/CVE-2026-118663