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

August 7, 2026

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.

References

github.com/advisories/GHSA-54fx-42gc-7vw4
github.com/honojs/hono/commit/f70e2c31684387b3231cc38512a31df6ca76a1c7
github.com/honojs/hono/releases/tag/v4.12.34
github.com/honojs/hono/security/advisories/GHSA-54fx-42gc-7vw4
nvd.nist.gov/vuln/detail/CVE-2026-71848

Code Behaviors & Features

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