Hono: Algorithmic Complexity DoS in Language Middleware

Summary The languageDetector middleware is vulnerable to algorithmic complexity denial of service when processing a crafted language tag containing a large number of hyphen-separated subtags. Details To implement progressive language-tag truncation, normalizeLanguage repeatedly calls parts.slice0...

CVE-2026-71848 Hono: Algorithmic Complexity DoS in Language Middleware

Hono is a Web application framework that provides support for any JavaScript runtime. From 4.12.0 to 4.12.33, the languageDetector middleware is vulnerable to algorithmic complexity denial of service when processing a crafted language tag containing a large number of hyphen separated subtags. To...

CVE-2026-71848

Summary: CVE-2026-71848 affects the Hono web framework (4.12.0–4.12.33) via the languageDetector middleware. The root cause is an implementation in normalizeLanguage() that builds language tag prefixes with parts.slice(0, i).join('-') for every possible prefix, causing the total string processing...