Medium

Hono has Body Limit Middleware Bypass

  • Disclosed: 12.09.2025
  • Updated: 11.10.2026 10:22

Summary

A flaw in the bodyLimit middleware could allow bypassing the configured request body size limit when conflicting HTTP headers were present.

Details

The middleware previously prioritized the Content-Length header even when a Transfer-Encoding: chunked header was also included. According to the HTTP specification, Content-Length must be ignored in such cases. This discrepancy could allow oversized request bodies to bypass the configured limit.

Most standards-compliant runtimes and reverse proxies may reject such malformed requests with 400 Bad Request, so the practical impact depends on the runtime and deployment environment.

Impact

If body size limits are used as a safeguard against large or malicious requests, this flaw could allow attackers to send oversized request bodies. The primary risk is denial of service (DoS) due to excessive memory or CPU consumption when handling very large requests.

Resolution

The implementation has been updated to align with the HTTP specification, ensuring that Transfer-Encoding takes precedence over Content-Length. The issue is fixed in Hono v4.9.7, and all users should upgrade immediately.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package hono < 4.9.7 4.9.7

References

CVSS score 5.3/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE)
CWE-400, CWE-770
Platform
npm
Package
hono
Disclosed
12.09.2025
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-92vj-g62v-jqhh - CC BY 4.0

Vulnerability history: hono

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (52) in the archive
Total entries
52
First → latest
12.2023 10.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 7
  • Medium 41
  • Low 4

Disclosures per year

  1. 2023: 1
  2. 2024: 3
  3. 2025: 4
  4. 2026: 44
Severity:
  1. High · 8.1 CVE-2025-62610 >= 1.1.0, < 4.10.2 4.10.2
  2. Hono has Body Limit Middleware Bypass this entry
    Medium · 5.3 CVE-2025-59139 < 4.9.7 4.9.7
  3. High · 7.5 CVE-2025-58362 >= 4.8.0, < 4.9.6 4.9.6

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