CVSS 3.1
5.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NCVE-2026-126356
Hono: `validator('form')` skips validation for `multipart/form-data` requests with extra parameters
Medium (5.3) in honojs hono. Fixed in hono 4.13.16.
On this page
Hono is a Web application framework that provides support for any JavaScript runtime. From 4.5.1 until 4.13.16, validator('form') uses a strict whole-header pattern that fails to recognize multipart/form-data when its Content-Type includes another legal parameter or extra whitespace after a semicolon. The validation callback receives an empty object even though c.req.parseBody() or c.req.formData() can still parse and expose all submitted fields to the handler. An unauthenticated client can therefore bypass allow-list or required-field checks when the application relies on the form validator and its callback accepts an empty object. application/x-www-form-urlencoded requests are not affected. This issue is fixed in version 4.13.16.
Severity
- OWASP Top 10
- A05:2025 Injection
- Published
- Modified
- Assigned by
- GitHub_M (CNA)
- NVD analysis
- Not in the NVD yet
- Record from
- the CVE List, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| honojs hono | >= 4.5.1, < 4.13.16 |
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-4h7h-rv7c-7m2v | npm | hono | >=4.5.1 <4.13.16 | 4.13.16 |
Attack patterns (CAPEC)
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits. More on the page of CWE-20 (51).