CVE-2026-42004

An attacker can send a crafted EDNS OPT record that will be ignored by DNSdist’s filtering rules, but will be rewritten as a valid OPT record when EDNS Client Subnet is inserted, causing the backend to see the EDNS option(s) that DNSdist did not filter.

Score

CVSS 3.1 3.7 Low

Status

Deferred - security@open-xchange.com

Published

2026-06-25

Last modified

2026-10-25

Weaknesses

CWE-115

Affected products

• Dnsdist (Powerdns)

References

• https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-09.html