Vulnerability Database

309,961

Total vulnerabilities in the database

CVE-2019-9900

When parsing HTTP/1.x header values, Envoy 1.9.0 and before does not reject embedded zero characters (NUL, ASCII 0x0). This allows remote attackers crafting header values containing embedded NUL characters to potentially bypass header matching rules, gaining access to unauthorized resources.

  • Published: Apr 25, 2019
  • Updated: Nov 9, 2025
  • CVE: CVE-2019-9900
  • Severity: High
  • Exploit:

CVSS v3:

  • Severity: High
  • Score: 8.3
  • AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L

CVSS v2:

  • Severity: High
  • Score: 7.5
  • AV:N/AC:L/Au:N/C:P/I:P/A:P

CWEs:

Software From Fixed in
envoyproxy / envoy - 1.9.0.x