fastify is vulnerable to header validation bypass via case-sensitive propertyNames

影響: npm:fastify >= 5.12.2, < 5.12.6 → 5.12.6

Fastify lowercases header names in a headers schema before compilation, because Node.js stores request header names in lowercase. This normalization does not reach the header names held in a propertyNames subschema's enum and const. A header-name deny-list written in the canonical header case, such as propertyNames: { not: { enum: ['X-Debug-Override'] } }, therefore never matches the lowercased request headers, and the forbidden header reaches the handler. Any application that uses a propertyNa…

GitHub Advisory Databaseで読む

2026/10/23 01:40、GitHub Advisory Databaseが「fastify is vulnerable to header validation bypass via case-sensitive propertyNames」を公開しました (種別: 脆弱性アドバイザリ)。重大度は「注意」(low) です。関連する技術: JavaScript / Node.js。CVE: CVE-2026-107832。