This page tracks the Debian fix status. The vulnerability itself is described on the main CVE page. View CVE-2026-42004 →

DEBIAN-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 EDN...

Original description

The description as published by the source.

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.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Affected packages

Debian:12 dnsdist

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Debian:13 dnsdist

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.15-0+deb13u1"}]}]

Debian:14 dnsdist

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.1.0-1"}]}]

References

advisory security-tracker.debian.org