Inefficient Algorithmic Complexity in hono - #VU140824
Published: August 3, 2026
Vulnerability identifier: #VU140824
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-407
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to algorithmic complexity in languageDetector middleware when processing crafted language tags with a large number of hyphen-separated subtags. A remote attacker can send a specially crafted request to cause a denial of service.
Language values may be sourced from a query parameter, cookie, Accept-Language header, or URL path depending on configuration, and the default detector order exposes query-string, cookie, and header-based processing.
Affected software
hono
Remediation
Install security update from vendor's website.
hono - update to 4.12.34