honojs Hono up to 4.13.15 Form Validation validator form input validation

Summaryinfo

A vulnerability, which was classified as problematic, has been found in honojs Hono up to 4.13.15. The affected element is the function validator of the component Form Validation. Performing a manipulation of the argument form results in input validation. This vulnerability was named CVE-2026-126356. The attack may be initiated remotely. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in honojs Hono up to 4.13.15. This affects the function validator of the component Form Validation. The manipulation of the argument form with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on integrity. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-126356 since 11/10/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 4.13.16 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• honojs

Name

• Hono

Version

• 4.13.0
• 4.13.1
• 4.13.2
• 4.13.3
• 4.13.4
• 4.13.5
• 4.13.6
• 4.13.7
• 4.13.8
• 4.13.9
• 4.13.10
• 4.13.11
• 4.13.12
• 4.13.13
• 4.13.14
• 4.13.15

Website

• Product: https://github.com/honojs/hono/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion