Input validation error in ISC BIND - CVE-2019-6469
Published: July 23, 2026
Vulnerability identifier: #VU139204
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-6469
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 the EDNS Client Subnet (ECS) feature for recursive resolvers when processing a response with malformed RRSIGs. A remote attacker can cause a server to perform a query whose answer is accompanied by malformed RRSIGs to cause a denial of service.
Only servers using the recursive ECS feature are vulnerable.
Affected software
ISC BIND
How to mitigate CVE-2019-6469
Install security update from vendor's website.
ISC BIND - update to 9.11.7-S1