Resource exhaustion in hono - CVE-2025-59139
Published: July 24, 2026
Vulnerability identifier: #VU139325
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: CVE-2025-59139
CWE-ID: CWE-400
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 uncontrolled resource consumption in the bodyLimit middleware when handling requests with conflicting Content-Length and Transfer-Encoding headers. A remote attacker can send a specially crafted request with an oversized chunked body to cause a denial of service.
The practical impact depends on the runtime and deployment environment, as some standards-compliant runtimes and reverse proxies may reject such malformed requests.
Affected software
hono
How to mitigate CVE-2025-59139
Install security update from vendor's website.
hono - update to 4.9.7