CVE-2026-71848 (GCVE-0-2026-71848)

Vulnerability from cvelistv5 – Published: 2026-08-07 18:36 – Updated: 2026-08-08 03:04
VLAI
Title
Hono: Algorithmic Complexity DoS in Language Middleware
Summary
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 implement progressive language tag truncation, normalizeLanguage() repeatedly calls parts.slice(0, i).join('-') for every possible prefix, so the total amount of string processing grows quadratically with the number of subtags. Language values may come from a query parameter, cookie, Accept-Language header, or URL path, depending on the detector configuration, and the default detector order enables query string, cookie, and header detection, so applications using languageDetector() may expose this processing to unauthenticated requests. An attacker may repeatedly send requests containing long, hyphen separated language tags, causing excessive CPU consumption and preventing unrelated requests from being processed. This issue is fixed in version 4.12.34.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-08 03:04 UTC
CWE
  • CWE-407 - Inefficient Algorithmic Complexity
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7974 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
honojs hono Affected: >= 4.12.0, < 4.12.34
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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