All vulnerabilities

Servers and applications

CVE-2019-18802

An issue was discovered in Envoy 1.12.0. An untrusted remote client may send an HTTP header (such as Host) with whitespace after the header content. Envoy will treat "header-value " as a different string from "header-value" so for example with the Host header "example.com " one could bypass "example.com" matchers.

Severity
Critical 9.8
Published
13 Dec 2019
Last changed
17 Jun 2026
Added to UpHeron
1 Nov 2026
Exploit chance
2.5% in the next 30 daysHigher than 84% of CVEs. EPSS by FIRST, 10 Nov 2026
Sources
NVD

Affected software

SoftwareAffected versions
EnvoyServers and applications · cpe:a:envoyproxy:envoy
  • Every version up to 1.12.1

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2019-18802
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2019-18802