{"affected":[{"product":"hono","source":"CNA: GitHub_M","vendor":"honojs","versions":[{"status":"affected","version":">= 4.5.1, < 4.13.16"}]}],"cveId":"CVE-2026-126356","cwes":["CWE-20","CWE-1471"],"description":"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.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":5.3,"severity":"medium","source":"CNA: GitHub_M","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"}],"modifiedAt":1794521855051,"publishedAt":1794521797256,"references":[{"source":"CNA: GitHub_M","tags":["x_refsource_CONFIRM"],"url":"https://github.com/honojs/hono/security/advisories/GHSA-4h7h-rv7c-7m2v"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/honojs/hono/commit/d88fab372415277a9e540e895650943dd08eef4a"},{"source":"CNA: GitHub_M","tags":["x_refsource_MISC"],"url":"https://github.com/honojs/hono/releases/tag/v4.13.16"}],"remediation":[],"revision":"66d836cf3a2371429bde4b5d507ff9a18317983561f08986725cf22ca14454da","sources":[{"modifiedAt":1794521855051,"name":"CNA: GitHub_M","retrievedAt":1794524922275,"url":"https://www.cve.org/CVERecord?id=CVE-2026-126356"}],"ssvc":null,"status":"published","title":"Hono: `validator('form')` skips validation for `multipart/form-data` requests with extra parameters","updatedAt":1794524922275}