Input validation error in envoy - CVE-2019-18838
Published: December 10, 2019 / Updated: August 26, 2026
Vulnerability identifier: #VU145858
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-18838
CWE-ID: CWE-20
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 improper input validation in host header request handling when processing requests without a Host header. A remote attacker can send a specially crafted request to cause a denial of service.
Affected software
envoy
How to mitigate CVE-2019-18838
Install security update from vendor's website.
envoy - update to 1.12.2