EDNS Client Subnet Vulnerability in DNSdist by PowerDNS
CVE-2026-42004

3.7LOW

Key Information:

Vendor

Powerdns

Status
Dnsdist
Vendor
CVE Published:
25 June 2026

What is CVE-2026-42004?

A vulnerability in DNSdist allows attackers to send a specially crafted EDNS OPT record, bypassing DNS filtering rules. This manipulated record is then rewritten to appear valid when EDNS Client Subnet is inserted. As a consequence, the backend server receives EDNS options that were initially ignored by DNSdist, potentially exposing it to further exploits and compromised security.

Affected Version(s)

DNSdist 1.9.0 < 1.9.15

DNSdist 2.0.0 < 2.0.7

References

https://www.dnsdist.org/security-advisories/powerdns-advi...

CVSS V3.1

Score:
3.7
Severity:
LOW
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Vitaly Simonovich
.